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MicroDaq-Mk2
Covering MicroDaq2,
FlightDaq2, CANdaq5 and
FlightDAQ-TL
USER PROGRAMMING
GUIDE
info@chell.co.uk
e-mail:-
Visit the Chell website at:
http://www.chell.co.uk
Chell Instruments Ltd
Folgate House
Folgate Road
North Walsham
Norfolk NR28 0AJ
ENGLAND
Tel:
01692 500555
Fax:
01692 500088
900204-1.7
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Table of Contents
Related Manuals for Chell MicroDaq-Mk2
Summary of Contents for Chell MicroDaq-Mk2
- Page 1 Chell Instruments Ltd Folgate House Folgate Road North Walsham Norfolk NR28 0AJ ENGLAND Tel: 01692 500555 Fax: 01692 500088 MicroDaq-Mk2 Covering MicroDaq2, FlightDaq2, CANdaq5 and FlightDAQ-TL USER PROGRAMMING GUIDE info@chell.co.uk e-mail:- Visit the Chell website at: http://www.chell.co.uk 900204-1.7...
- Page 2 Use of this equipment in a manner not specified in this manual may impair the user’s protection. Chell Document No. : Issue 1.7 900204 ECO: 3802 Date: 16 June 2020 Chell’s policy of continuously updating and improving products means that this manual may contain minor...
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Page 3: Table Of Contents
4.1.5 Control Via TCP............................10 4.2. UDP ............................11 4.2.1 Overview ..............................11 4.2.2 Connection ..............................11 4.2.3 Chell UDP Protocol ............................. 11 4.2.4 UDP Data Rate............................13 4.2.5 Control Via UDP............................13 4.3. Timestamping ..........................14 4.4. -
Page 4: Introduction
Although for many applications this is enough, more demanding applications may need to control the data delivery, request data rezero operations and more. The microDAQ-Mk2 has the same user interface protocol taken from the microDAQ system, allowing remote access to the essential commands required when integrating the unit into an instrumentation system. -
Page 5: User Command Protocol
2. User Command Protocol. 2.1. Command Packet. The command protocol is based around a simple delimited control packet, allowing easy identification of command start and end. The packet includes a block parity byte increasing the robustness of transmission; the packet format is shown in Figure 2.1. >... - Page 6 Rate V/86 byte = 0xab Adjust the data delivery rate for each communication channel. The upper nibble of the parameter byte selects which communication a = 1 TCP / UDP channel, while the lower selects its data rate. a = 2 CAN CAN &...
- Page 7 b = 0 : 16 bit LE Pressure data is available in engineering units over UDP, TCP and RS232 b = 1 : 16 bit BE connections, though only binary data is available with CAN and Internal b = 2 : Engineering RAM.
- Page 8 Poll O/79 1 - TCP / UDP Request a single data packet (in the current active format) for the 2 – CAN channel selected. Data streaming should be set off before using this command. Note that there is no positive acknowledge for this command.
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Page 9: Status Data Format
3. Status Data Format. 3.1. MicroDaq & FlightDaq Status data is not currently supported over the CAN channel, however for TCP connections, status data may be requested from the microDAQ as three forms – ‘short’, ‘full’ and ‘with temp’. The short form returns 4 bytes, the 16 bit status word delimited by the ASCII characters ">"... -
Page 10: Communication Channels
0 to 65535 (zero at 32767). Scaling to floating point full scale is better achieved within a PC client application where there is more processing power available. 16bit, little endian (microDAQ-Mk2) Header Channel1 Data... - Page 11 16bit, big endian (microDAQ-Mk2) Header Channel1 Data Channel 2 Data Channel 3 Data 0x00 0xFF 0x00 …. Channel ’N’ Data 3 byte header identifies the start of the packet, followed by all channels (1 to ‘N’ where ‘N’ = 16, 32...
- Page 12 Single character header followed by all channels (1 to ‘N’ where ‘N’ = 16 or 32 depending on setting), 5 decimal places, comma delimited. (flightDAQ-TL returns 6 decimal places). Note that flightDAQ-Mk2 includes the Abs sensor data in the same format, comma separated, just before Channel 1 Data. Figure 4.1, Data Packet Protocol, TCP Channel.
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Page 13: Tcp Data Rate
4.1.4 TCP Data Rate. The data delivery rate is selected from the setup program, the available rates vary depending on the product type, see the RATE command in Section 2.3. Although the system endeavours to deliver the rate with maximum accuracy, ultimate responsibility for data timing lies with the user’s host system. When using microDAQ or flightDAQ products with pressure scanners, note that since the scanners are addressed at a fixed channel rate (20kHz if configured for Gen1 scanners, 50kHz if configured for Gen2 scanners), requesting a data delivery of more than 20k/No. -
Page 14: Udp
As with TCP the microDAQ’s UDP channel affords it the ability to stream real time pressure data at high speed over standard 100Mbit Ethernet connections. The microDAQ supports two data stream formats, the Chell data stream format and an IENA specification output, which can be setup from the web server. - Page 15 4 byte header containing the unit serial number (32bit IEEE754 encoded) identifies the start of the packet, followed by a packet number (32bit IEEE754 encoded), followed by all channels (1 to ‘N’ where ‘N’ = 16, 32 or 64 depending on setting), MSB first, with no delimiters 16 Bit, little endian (flightDAQ-Mk2) Header (serial num.) Packet Number...
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Page 16: Udp Data Rate
4.2.4 UDP Data Rate. The UDP data rate is much the same as the TCP data rate in its configuration and use, so all the TCP data rate information is applicable for UDP. 4.2.5 Control Via UDP. A positive acknowledgement is returned as ‘**’ and a negative acknowledgement as ‘!!’. The argument regarding loss of acknowledgements in the data stream holds good for the UDP channel, and it is recommended that a ‘Stream Off’... -
Page 17: Timestamping
4.3. Timestamping In addition to the above, standard data streaming over both TCP & UDP can include time stamping information to aid with synchronisation of data packets. The device keeps track of time to microsecond resolution since it was powered on but this can be turned into a real time by either synchronising the time with a PC (via the webserver) or for a more accurate time sync, by using a PTP grandmaster to provide a constant PTP sync message. - Page 18 microDAQ flightDAQ 1(LSB) Synced to external time Synced to external time Synced to PTP master clock Synced to PTP master clock Device within user defined temperature range Heaters are on Device is over 90 degC Following this is a rolling 16 bit sequence number that counts how many packets have been sent in this data stream, this is a rolling counter, so if the packet sent is greater than the maximum value this field can hold then it will reset to 0 and start counting again.
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Page 19: Can
4.5. CAN 4.5.1 Overview The CAN channel is somewhat different to the above channels, in that it is not a simple serial communications channel, the data being sent in discrete chunks on specified message identifiers. CAN is not supported on the flightDAQ-TL device 4.5.2 CAN Baudrate The microDAQ offers a single ‘standard’... - Page 20 Message ID Data Byte 0x220 0x221 0x222 0x223 0x224 0x225 0x226 0x227 CH12 CH16 CH20 CH24 CH28 CH32 CH12 CH16 CH20 CH24 CH28 CH32 CH11 CH15 CH19 CH23 CH27 CH31 CH11 CH15 CH19 CH23 CH27 CH31 CH10 CH14 CH18 CH22 CH26 CH30 CH10...
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Page 21: Can Data Rate
4.5.4 CAN Data Rate The data delivery rate is selected from the setup program, and the following values are available (Hz) – 1, 2, 5, 10, 25, 50, 100, 312, 500, 625, 750, 1000. Although the system endeavours to deliver the rate with maximum accuracy, ultimate responsibility for data timing lies with the user’s host system. -
Page 22: Internal Ram
4.6. Internal RAM 4.6.1 Overview Data acquisition to internal RAM allows for fast acquisition without the potentially limiting factor of external comms hardware (e.g. network hubs, PC CAN interfaces, etc.). Data can be acquired at whatever speed is necessary and then dumped to the host PC as a post-acqusition task. Logging to RAM is not supported on the flightDAQ 4.6.2 Internal RAM Protocol The data protocols available for internal RAM storage are 16bit little endian or big endian only. - Page 23 ‘Blocks per op’ details the number of cycles of ‘n’ channels that are sent in one transmission packet – this is dependant on the number of channels being acquired (byte 3 in header above) and is irrelevant for CAN (always set to 1). After each packet is sent, the microDAQ waits for a handshake to confirm that the packet of data has been received at the host PC end.
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Page 24: Valve Control User Commands
5. Valve Control user commands The flightDAQ unit contains both microDAQ hardware and additionally contains two solenoid valves to control the shuttle of the Measurement Specialties scanners that are part of the flightDAQ unit and also contains an electrical drive signal for controlling an external purge valve. The microQDVP module is an accessory to the microDAQ unit that also contains the valving and drive signal.
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