Related Manuals for Elpro Technologies 455U-D
Summary of Contents for Elpro Technologies 455U-D
- Page 1 User Manual 455U-D Radio Modem ELPRO Technologies Pty Ltd, 9/12 Billabong Street, Stafford Q 4053, Australia. Tel: +61 7 33524533 Fax: +61 7 33524577 Email: sales@elprotech.com Web: www.elprotech.com...
- Page 2 Contents Thank you for your selection of the 455U-D radio modem. We trust it will give you many years of valuable service. ATTENTION! Incorrect termination of supply wires may cause internal damage and will void warranty. To ensure your 455U-D enjoys a long life, double check ALL your connections with the user’s manual...
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Page 3: Warning
455U-D Radio Modem Module User Manual How to Use This Manual To receive the maximum benefit from your 455U-D product, please read the Introduction, Installation and Configuration chapters of this manual thoroughly before putting the 455U-D to work. Chapter Four Specifications details the features of the product and lists the standards to which the product is approved. -
Page 4: Table Of Contents
Contents CONTENTS WARNING ..........................4 CHAPTER ONE INTRODUCTION ..............8 ......................... 8 ENERAL 1.1.1 Basic Operation ......................9 1.1.2 Operating Modes ....................... 9 1.1.3 Repeater Functionality..................... 10 1.1.4 Hot Redundant Standby................... 10 ..................10 NACKNOWLEDGED ..................11 CKNOWLEDGED ..................14 ECURITY NCRYPTION .................. - Page 5 455U-D Radio Modem Module User Manual CHAPTER THREE CONFIGURATION................ 31 ................... 31 EFORE ONFIGURING 3.1.1 Addressing ....................... 31 3.1.2 Command Mode ...................... 32 ..................32 EFAULT ONFIGURATION ................... 32 ONFIGURATION ROGRAM 3.3.1 Reading and Configuring a module................. 33 ............35...
- Page 6 Contents 4.4.1 Bit Error Ratio Test (BER)..................57 4.4.2 Other Radio Testing - AT&Tx ................58 4.4.3 On-line diagnostics ....................59 .................... 61 ADIO ESTING ..............62 HANGING THE ADIO ARAMETERS ..................63 IAGNOSTIC ESSAGES ..................... 64 EDUNDANCY 4.8.1 Firmware versions prior to 3.03 ................67 CHAPTER FIVE SPECIFICATIONS ................
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Page 7: Chapter One Introduction
Examples of host devices are PLC’s, data loggers, intelligent transducers and computers. The 455U-D unit can receive data from the host device and transmit this data by radio to another (or several) 455U-D module. The other module will recreate the serial data and output it as either a RS232 or RS485 serial signal. -
Page 8: Basic Operation
(user configurable - default 1020 bytes). If more than 1020 bytes is input, the 455U-D unit will transmit the first 1020 bytes, then the next 1020 bytes, and so on until all of the data has been transmitted. -
Page 9: Repeater Functionality
User Manual 1.1.3 Repeater Functionality A 455U-D unit can act as a repeater for other units. A repeater receives a radio message from one unit and re-transmits it on to another unit. Up to seven repeater addresses can be configured in a radio link. -
Page 10: Acknowledged Mode
DATA DATA 455U-D module, or to all modules by using address 0. Data received from the UNACKNOWLEDGED MODE ADDRESSED TO ALL UNITS USING radio with the correct... - Page 11 Once the communications channel has been established, the 455U-D unit will accept input data and send radio messages with data. When a 455U-D unit receives a radio message, it will check the system address and destination address, and also the error-check (optional). If these are correct, it will return a ACK (acknowledgment) message to the source unit.
- Page 12 Chapter One Introduction If the source unit does not receive an ACK message, it will re-transmit the same message. It will attempt to transmit the message the configured number of times (S-Register S30). If the unit still does not receive an ACK message after the configured number of attempts, it will reset the LINK LED, and reset the DCD output on the DB9 RS232 port and reset the DIO output (if configured).
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Page 13: Security Encryption
8Kbytes of data, and CTS/RTS control can be configured on the RS232 port to prevent overflow. When the 455U-D unit detects data in the input buffer, it initiates a radio message. The radio message will end when the number of transmitted bytes reaches the maximum message length (configurable by the user), or if the input buffer becomes empty. -
Page 14: Plc-Mode
1.5.1 PLC-Mode The 455U-D will operate most efficiently when the serial data rate is higher or the same as the radio data rate. If the serial data rate is less than the radio rate, there is a risk that the radio will empty the input buffer too quickly, resulting in a single input message being broken into more than one output messages. -
Page 15: Serial Data Rate
9600, or 19200 bits/second - (19200 baud only operates with 25KHz channel widths). The user must configure the radio data rate at each 455U-D module. The configured radio data rates must be the same for each module in a system. -
Page 16: Addressing
A 455U-D must also be configured with a “unit” address - this gives the module a unique identification. The unit address is used to identify the two data ports on each 455U-D. The RS232 port is accessed by addressing the configured unit address. -
Page 17: Optimum Path Routing
• The device connected to the RS485 port can link to the RS485 port or the RS232 port on another 455U-D - the same applies to the RS232 device. However if a wild-card address is used (0 or 128), then all remote serial ports must be the same - that is, all R485 or all RS232. -
Page 18: Duty Cycle Limiting
It is possible to configure different units in the same system with different operating modes, however this requires care. A 455U-D unit configured in one mode can act as a repeater for messages sent between two 455U-D units configured in the other mode, and it is always possible to send Unacknowledged mode messages to the RS-485 port on a module regardless of the configuration of the RS-232 port. -
Page 19: Error Check
Error-check is strongly recommended for Acknowledged mode operation. If error-check is not configured, then a 455U-D unit will transmit an acknowledgment message (ACK) whenever it receives a radio message, without checking for errors. If error-check is configured, the unit will only transmit an ACK message if the error-check is correct. -
Page 20: Chapter Two Installation
Further information is detailed below. Each 455U-D module should be effectively earthed via the "GND" terminal on the 455U-D module - this is to ensure that the surge protection circuits inside the 455U-D module are effective. Antenna Installation The 455U-D module will operate reliably over large distances. - Page 21 455U-D Radio Modem Module User Manual ground for paths of 5 km (3 miles). For short distances, the modules will operate reliably with some obstruction of the radio path. Obstructions which are close to either antenna will have more of a blocking effect than obstructions in the middle of the radio path. For example, a group of trees around the antenna is a large obstruction, and the antenna should be raised above the trees.
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Page 22: 3Db/6Db Collinear Antenna
PVC insulating tape. Where antennas are mounted on elevated masts, the masts should be effectively earthed to avoid lightning surges. Although the 455U-D module is fitted with surge protection, additional surge suppression devices are recommended if lightning surge problems are experienced. If... -
Page 23: Yagi Antennas
Power Supply The 455U-D has a 15-28VDC “normal” supply and a 12 - 15VDC alternate supply. The supply requires a minimum capacity of 24 Watt for the high power radio version (0.5-5W) or 6W for the low radio power version (10 –... - Page 24 The DC supply may be a floating supply or negatively earthed. The power requirements of the 455U-D units at 12VDC is 110mA (quiescent) and 2A when transmitting (5 Watt), or 450mA for 500mW. Power Earth 15 –...
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Page 25: Serial Connections
Hardware handshaking using the CTS/RTS lines is provided. The CTS/RTS lines can be configured to reflect the status of the local unit’s input buffer. The 455U-D supports XON/XOFF flow control. Example cable drawings for connection to a DTE host (a PC) or another DCE host (or modem) are detailed below. -
Page 26: Rs232 Configuration Port
Request to Send 2.4.3 RS485 Serial Port The RS485 port provides for communication between the 455U-D unit and its host device using a multi-drop cable. Up to 32 devices may be connected in each multi-drop network. As the RS485 communication medium is shared, only one of the units on the RS485 cable may send data at any one time. -
Page 27: Discrete I/O Point
If the module is not at one end of the RS485 cable, the switch should be off. Discrete I/O Point The 455U-D provides a single connection which can be used as a discrete input for alarms, or a discrete output, to control remote equipment, 2.5.1 Using the Discrete I/O as an Output... -
Page 28: Dual Redundant Installation
Installation Dual Redundant Installation Two 455U-D units can be connected together in a dual redundant arrangement. One unit configured as a Primary is normally active, and the Secondary unit is inactive. If the Primary detects an internal fault or operating problem, then the Primary unit becomes inactive and the Secondary becomes active. - Page 29 455U-D Radio Modem Module User Manual messages. Redundant Host Pair If the host device is duplicated as a redundant pair, with an individual host connected to an individual 455U, then RS232 should be used - the 455U will receive and send serial messages, however only the active 455U will transmit via the radio.
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Page 30: Chapter Three Configuration
• Addressing - system address and unit address. • Character type. You need to find out the character type of the host devices connected to the 455U-D units. The most common character type is 8 data bits, no parity, 1 start bit and 1 stop bit. -
Page 31: Command Mode
Each module is also configured with a unit address between 1 and 127 - this gives the module a unique identification. The two data ports on the 455U-D can be addressed based on the unit address. The RS232 port is accessed using the unit address, and the RS485 port is accessed using the configured unit address +128. -
Page 32: Reading And Configuring A Module
System screen. 3.3.1 Reading and Configuring a module You will need a connection cable between the PC and the 455U-D. The cable may connect to either the DB9 port or the RJ45 configuration port. Connecting to the RJ45 configuration port allows the modem to be configured while the DB9 port remains connected to the functioning Man_455U-D Rev 3.03... - Page 33 455U-D Radio Modem Module User Manual host system. Connecting to the RJ45 port also allows configuration of remote modems in the system. The cable to connect to the DB9 should have straight-through connections as per section 2.4.1 of this manual. If your PC only has USB serial connections with no RS232 port, you will need to purchase a USB to RS232 converter cable.
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Page 34: Remote Configuration And Diagnostics
Configuration Remote Configuration and Diagnostics Most of the configuration features of the 455U-D modem can be accessed remotely over the radio network. Remote configuration is accessed by connecting to the RJ-45 configuration port on the local modem, and using either the configuration software or AT commands. Refer to section 3.3.1 for information on setting up the PC Com port. -
Page 35: Unacknowledged Mode
455U-D Radio Modem Module User Manual Using AT commands: Connection to the remote modem is accessed using the ATD command on the local RJ-45 configuration port: ATDxxx Remote Configuration and Diagnostics Access (RJ45 port only) ATD3 Access remote diagnostics on station address 3... -
Page 36: Rs-232 Port
3.5.2 RS-232 Port The RS232 port can be configured for “auto connect” or “single connect”. Auto connect means that the 455U-D will start up online. This will be indicated by the LINK LED going green. Single connect means that the unit will start up in command mode, and will not go online until it receives the correct AT command. -
Page 37: Unacknowledged Mode Repeaters
(0 or 128) to send messages to multiple units in the system. 3.5.3 Unacknowledged mode Repeaters Every 455U-D module automatically acts as a repeater by including its address in the address list. For example, if unit 31 receives a message with address <31,15>, it will repeat the message onto unit 15. - Page 38 Chapter Three Configuration Broadcast Network You may want a multi-hop network to broadcast messages. This takes some care at the repeater nodes to ensure that individual repeaters do not repeat messages that they have already repeated, and also to avoid a “end-node” receiving the same message multiple times. Note - Before deciding to implement a multi-hop broadcast network, check the section below on Optimum Path Routing.
- Page 39 455U-D Radio Modem Module User Manual The first ring of repeaters (units 14 and 15) need to be configured as below: The “Repeat Messages to address 0” box is selected to allow these units to repeat the broadcast messages on.
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Page 40: Multiple Transmissions
“Flow control” affects the use of the CTS and RTS signals on the RS232 port. These signals can be used to prevent overflow of the input buffer or output buffer of the 455U-D. The settings should be selected to match the host device. The options for this setting are : “None”... -
Page 41: Other Settings
The DTR signal on the RS232 port can be used for different functions. “Ignore DTR” - the DTR signal does not perform any function “Command Mode” - if the host resets DTR, the 455U-D will go into command mode - when DTR is activated, the module will revert to on-line mode “Command Mode, Disconnect”... -
Page 42: Acknowledged Mode
Packet Size (bytes) This selects the maximum number of bytes which will be transmitted in one message. If more than this number of bytes is input into the 455U-D, then the module will transmit more than one message. The default value is 1020 bytes which is the largest packet value. If you are operating in a... - Page 43 455U-D Radio Modem Module User Manual If there is no data transfer within the preconfigured “link check” time, the master will send an empty data message to check the communications link. The connection will be broken if a communication failure occurs, or if the local or remote hosts issues a “disconnect”...
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Page 44: Single-Connect Acknowledged Mode
Connect message from the master unit. If you enter an “Inactivity Timeout” value, then the 455U-D will automatically reset the link if there has been no data transmissions within this time. If you use the link check feature at the master unit, you should enter an “Inactivity Timeout”... -
Page 45: Dual Redundant Standby
Dual Redundant Standby Two 455U-D units can be connected together in a hot-redundant-standby arrangement. One unit configured as a Primary is normally active, and the Secondary unit is inactive. If the Primary detects an internal fault or operating problem, then the Primary unit becomes inactive and the Secondary becomes active. - Page 46 Chapter Three Configuration If using Hayes commands, Dual Redundancy is set via the AT#O command (“set output function”). ♦ to force a changeover from primary to secondary, use command AT#O5. ♦ to force a changeover from secondary to primary, use the command AT#O6. ♦...
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Page 47: Low Power Mode
In this situation, the DTR signal from the host device is used to “wake-up” the 455U-D unit. The 455U-D unit will then operate normally until the DTR signal is reset by the host device. -
Page 48: Path Configuration
Chapter Three Configuration To use OPR, select “Use Host Protocol” in the “Operating Mode” section of the configuration screen. Select the host protocol type in the drop-down box below. (Modbus ASCII or RTU, DF1 or DNP3). Path Configuration When “Use Host Protocol” is selected, you can click the “Paths”... -
Page 49: Dnp3
ASCII messages designed for use with conventional telephone modems. Before a 455U-D unit will accept Hayes commands, it must be in “command” mode. The RJ- 45 configuration port is always in command mode. The DB9 RS-232 port needs to be set to command mode if the modem is currently communicating. -
Page 50: At Configuration Examples
DIP switch (refer section 3.10), or by using the AT&F command. If you are making a change to an existing configuration, this step is not necessary. Appendix A details all of the Hayes commands accepted by the 455U-D. The following commands are the most common. - Page 51 455U-D Radio Modem Module User Manual This example incorporates a single station connected to Master host device (Address 1), two repeater stations with connected slave host devices (Addresses 14 and 21), and a remote stations with a connected slave host device (Address 36).
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Page 52: Switch Configuration
Chapter Three Configuration ATS17=4 – Set the receive hold-off. This ensures that the repeated messages from the repeaters don’t clash with responses from the directly communicating device (address 15). This command sets the repeater to 200 msec hold-off. Slave devices Site address 36 AT&M0 - Configure mode 0 –... -
Page 53: Chapter Four Troubleshooting
TROUBLESHOOTING Power-up and Normal Operation When power is initially connected to the 455U-D module, the module will perform internal diagnostics to check its functions. The following table details the status of the indicating LEDs on the front panel under normal operating conditions. -
Page 54: Led Indication Diagnostics Chart
Chapter Four Troubleshooting LED indication Diagnostics Chart INDICATOR CONDITION MEANING • Power supply failure OK LED OFF Continuously • Battery Supply Overvoltage • Module Out of buffer memory (Host device ignores OK LED RED Briefly CTS) • Low Supply Current during transmit (Modem resets) •... -
Page 55: Operating Problems
Interference will only cause a problem if the amplitude of the interference is comparable to the radio signal from the 455U-D units. If the interference level is relatively small, then it will not affect the performance of the system. If interference is causing a problem, try to improve the normal radio level by mounting the antennas higher or in a better location. -
Page 56: Test Functions
Chapter Four Troubleshooting • If large radio messages are being transmitted, reduce the maximum message length, and transmit the data in more messages of smaller size. Another common problem is the response time of the host software. Some hosts operate by sending a message from one end and require a response to that message within a certain time. -
Page 57: Other Radio Testing - At&Tx
4.4.2 Other Radio Testing - AT&Tx To aid in the checking and setup of the 455U-D unit, diagnostic functions are provided using the standard Hayes AT commands. To perform the tests, you will need a terminal (PC + hyper- terminal) set-up to match the module (same character type and serial speed). -
Page 58: On-Line Diagnostics
Most radio tests are carried out using the AT&T2 test as this is the easiest to accomplish. AT&T5 - Received Signal Strength Display This option provides for testing the radio path between two 455U-D units. Although a pair of units may communicate successfully, radio communication may be affected by a range of influences, including atmospheric conditions, changing landscape, degradation of antennas or co-axial cable, low battery voltage etc. - Page 59 Battery Input Voltage (Units 0.1Volt) Supply Input Voltage (Units 0.1Volt) (0-25.5 Volts) The diagnostic information can be viewed using the configuration program while the 455U-D is online, by connecting via the secondary RJ45 RS232 port. The information is displayed under the “Radio Stats” tab on the right-hand side and the information refreshed (read from the connected module) by selecting the “Reload Radio...
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Page 60: Radio Path Testing
Chapter Four Troubleshooting Refresh Diagnostics information Radio Path Testing To carry out a radio path test, you will need two 455U modules. One module will be “fixed” and the other “mobile”. Both units will need power supplies and antennas. The power supply for the mobile unit is normally a 12V battery, but make sure that the battery is fully charged - batteries with low voltage will lead to low radio power which will affect the test result. -
Page 61: Changing The Radio Parameters
455U-D Radio Modem Module User Manual Take the mobile module to the other end of the radio path. The antenna at this end can be either held by the tester, or fixed in a temporary fashion. Note that a person’s body will affect the radiation pattern of an antenna, so if the antenna is hand-held and the test is not successful, try again with the antenna fixed to a 1 metre length of plastic pipe or timber. -
Page 62: Diagnostic Messages
Chapter Four Troubleshooting Diagnostic Messages The modem is configured to print diagnostic messages out the RS-232 Configuration port. At startup, this port displays the following messages. Firmware ELPRO E455U Modem firmware version Version V3.00 Configuration Config Loaded OK Configuration was loaded from EEPROM with no Load status fault detected Default Config Set... -
Page 63: Dual Redundancy
455U-D Radio Modem Module User Manual Dual Redundancy Two modems can be setup to act as a dual-redundant pair. If one modem fails, the second modem can take over the communications task. One of the modems is designated the Primary modem, and the other is designated the secondary. - Page 64 Chapter Four Troubleshooting • Use the configuration port to read the status of S-Register S-33 to check the dual redundancy status. S33 Value Dual Redundant State Active Primary Active Secondary Active Primary – no secondary detected Inactive Primary Inactive Secondary •...
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Page 65: User Manual
455U-D Radio Modem Module User Manual The following image shows the states of the dual redundant system, the relationship to the AT#O commands, the OK LED state, and S-registers S33 and S11 (Firmware versions 3.03 and later). Flash Red-Green With DIO LED... -
Page 66: Firmware Versions Prior To 3.03
Chapter Five Specifications 4.8.1 Firmware versions prior to 3.03 Firmware version 3.03 introduced enhanced diagnostics by flashing the OK LED in synchronisation with the DIO LEDs. For firwmare versions 3.00 to 3.02, refer to the following diagrams indicating the LED diagnostics and Redundancy state diagrams. LED Sequence Redundancy Status 1½... - Page 67 455U-D Radio Modem Module User Manual E455U-D Dual Redundant Control - Primary AT#O3 Get Control S33=2 Start Timeout (S11) Fault cleared Secondary Inactive Secondary Active Forced Standby S33=5 Standby S33=5 AT#O5 Fault Secondary Inactive Active No Secondary Responding Active Secondary...
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Page 68: Chapter Five Specifications
Chapter Five Specifications Chapter Five SPECIFICATIONS General EMC specification EN 301 489 FCC Part 15 Radio specification EN 300 113 RSS-119, AS 4768.1 EN 300 220 FCC Part 90, AS4295 Housing 140 x 114 x 30mm Powder-coated, aluminum 5.5 x 4.5 x 1.2 inch DIN rail mount Terminal blocks Removable... - Page 69 455U-D Radio Modem Module User Manual Receive Sens (BER 10 -106 dBm 9600 Baud 12.5KHz channel -112 dBm 4800 Baud -114 dBm 2400 Baud -116 dBm 1200 Baud Signal detect / RSSI -120 to -60 dBm Expected line-of-sight range 30 km @ 19200 baud...
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Page 70: Chapter Six Warranty & Service
Chapter Six Warranty Chapter Six WARRANTY & SERVICE We are pleased that you have purchased this product. ELPRO products are warranted to be free from manufacturing defects for the “serviceable lifetime” of the product. The “serviceable lifetime” is limited to the availability of electronic components. - Page 71 User Manual Appendix A Hayes Commands The following details all of the Hayes commands supported by the 455U-D. Default settings are shown by a “dot”, • Command Function Answer Incoming Call – The modem can also be set to answer incoming calls immediately or after a certain number of attempts.
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Page 72: Appendix Ahayes Commands
Appendix A Hayes AT Commands Set 187,500 baud (For Profibus) Connection/Dialing Control. Dial a specific remote or a stored number. This command has a different effect depending on whether it is issued from the RS- 232 main serial port (connects to the remote modem’s serial ports) or from the Diagnostic serial port (Connects to the remote modems diagnostic functions). - Page 73 455U-D Radio Modem Module User Manual Set 57,600 baud Set 76,800 baud Set 93,750 baud (For Profibus) Set 115,200 baud Set 187,500 baud (For Profibus) ATSn? Read value from S-Register n (Refer to Appendix C) ATSn=xx Set value of S-Register n to xx (Refer to Appendix C)
- Page 74 Appendix A Hayes AT Commands AT#E Encryption Mode (Use security menu AT#S to change encryption key) Disable security encryption #E0• Enable security encryption on transmitted messages Enable security encryption on transmitted messages and enforce encryption on received msgs. AT#N Enter Module Serial Number (11 characters Max) (Requires Radio Access AT#R to change).
- Page 75 455U-D Radio Modem Module User Manual DCD High when connected (Acknowledged Mode) or when online &C1• (Unacknowledged mode). Low otherwise. &C2 DCD Always on, Pulses low on Disconnect (Acknowledged Mode) or on Hangup (Unacknowledged mode). AT&D Data Terminal Ready (DTR) Behavior. The host controls DTR. This command controls how the modem reacts to the state of DTR.
- Page 76 Appendix A Hayes AT Commands Flow Control Disabled. CTS Always high. Modem ignores RTS. &K0• &K1 CTS/RTS Flow Control. CTS follows RTS high if there is space in the local buffer. Otherwise CTS goes low. On Serial Transmit, CTS goes high, and waits for RTS to go high before transmitting.
- Page 77 455U-D Radio Modem Module User Manual &M5 DNP3 Protocol AT&N Abort Connection Control. Controls whether the modem will abort a connection attempt if a character is entered. This item is only meaningful with the acknowledged mode of operation. &N0 Ignore characters entered while attempting to make a connection.
- Page 78 Appendix A Hayes AT Commands AT&T Self Tests. Allows in-field diagnostics, and factory testing. Tests time out after the period configured in S-Register S8 (if not zero). &T0 Stop Tone reversals (See T1 to T4 below). &T1 Transmit tones Modulated at 200 Hz &T2 Transmit tones Modulated at 2400 Hz &T3...
- Page 79 455U-D Radio Modem Module User Manual Set Radio to 4800 HZ bandwidth. AT\P Radio Power (Can only be set when #R Password entered) 5 Watt Radio .500 mW Radio Set Radio to 500 mW Set Radio to 10mW Set Radio to 1 W.
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Page 80: Appendix Bresponse Codes
Appendix B Response Codes Appendix B Response Codes Response codes display the status of the module in response to user commands. The response code displayed depends on the ATV setting, the ATX setting and the ATQ setting. ATV0 selects numeric response codes. ATV1 selects verbal response codes. The ATXn command selects extended response codes. -
Page 81: Appendix C S-Registers
455U-D Radio Modem Module User Manual Appendix C S-Registers The following table lists the S-Registers supported by the 455U-D modem. Range Function Comment 0-255 Attempts before Answering Should normally be set to 1. 0 disables auto Call answering of calls (ATA command to answer calls only). - Page 82 Appendix C S-Registers S12 = 6 “BUSY” response from remote modem on dial request. S12 = 7 Character received from host while attempting to connect S12 = 8 Hang-up from remote modem. 0-255 Spare Function Not Implemented 0-255 Max Packet (0–1020 bytes) Max Packet size = S14 x 4.
- Page 83 455U-D Radio Modem Module User Manual 0-255 System Address –High Byte The 16-bit system address uniquely identifies the radio network 0-255 System Address –Low Byte The 16-bit system address uniquely identifies the radio network 0-255 Lead-In Tone Time This selects the Lead-In tone period – units 4 msec.