Communications Protocols; Modbus - Teledyne T200 Operation Manual

Communications Setup and Operation

6.7. COMMUNICATIONS PROTOCOLS

6.7.1. MODBUS

Actions
Set Com Mode parameters
Comm
Slave ID
Reboot analyzer
Make appropriate cable
connections
Specify MODBUS software
settings
(examples used here are for
MODBUS Poll software)
Read the Modbus Poll
Register
136
Teledyne API – T200 NO/NO
Two communications protocols available with the analyzer are MODBUS and Hessen.
MODBUS setup instructions are provided here (Section 6.7.1) and registers are provided
in Appendix A. Hessen setup and operation instructions are provided in Section 6.7.2.
The following set of instructions assumes that the user is familiar with MODBUS
communications, and provides minimal information to get started. For additional
instruction, please refer to the Teledyne API MODBUS manual, PN 06276. Also refer to
www.modbus.org for MODBUS communication protocols.
Minimum Requirements

Instrument firmware with MODBUS capabilities installed.

MODBUS-compatible software (TAPI uses MODBUS Poll for testing; see
www.modbustools.com)

Personal computer

Communications cable (Ethernet or USB or RS232)

Possibly a null modem adapter or cable
Ethernet: Using the front panel menu, go to SETUP – MORE – COM – INET; scroll
through the INET submenu until you reach TCP PORT 2 (the standard setting is
502), then continue to TCP PORT 2 MODBUS TCP/IP; press EDIT and toggle
the menu button to change the setting to ON, then press ENTR. (Change
Machine ID if needed: see "Slave ID").
USB/RS232: Using the front panel menu, go to SETUP – MORE – COM – COM2 – EDIT;
scroll through the COM2 EDIT submenu until the display shows COM2
MODBUS RTU: OFF (press OFF to change the setting to ON. Scroll NEXT to
COM2 MODBUS ASCII and ensure it is set to OFF. Press ENTR to keep the
new settings. (If RTU is not available with your communications equipment, set
the COM2 MODBUS ASCII setting to ON and ensure that COM2 MODBUS
RTU is set to OFF. Press ENTR to keep the new settings).
If your analyzer is connected to a network with at least one other analyzer of the same model,
a unique Slave ID must be assigned to each. Using the front panel menu, go to SETUP –
MORE – COM – ID. The MACHINE ID default is the same as the model number. Toggle the
menu buttons to change the ID.
For the settings to take effect, power off the analyzer, wait 5 seconds, and power it on again.
Connect your analyzer either:
via its Ethernet or USB port to a PC (this may require a USB-to-RS232 adapter for your PC;

if so, also install the sofware driver from the CD supplied with the adapter, and reboot the
computer if required), or
via its COM2 port to a null modem (this may require a null modem adapter or cable).

Click Setup / [Read / Write Definition] /.
1.
In the Read/Write Definition window (see example that follows) select a Function (what
a.
you wish to read from the analyzer).
Input Quantity (based on your firware's register map).
b.
In the View section of the Read/Write Definition window select a Display (typically Float
c.
Inverse).
Click OK.
d.
Next, click Connection/Connect.
2.
In the Connection Setup window (see example that follows), select the options based on
a.
your computer.
Press OK.
b.
Use the Register Map to find the test parameter names for the values displayed (see example
that follows If desired, assign an alias for each.
/NO Analyzer Operation Manual
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06858E DCN7057