Yokogawa UT320-01 connectivity to MVI56-MCM Module
Problem Solution Overview
We performed testing between the subject device and our MVI56-MCM product.
Solution Brief
Our testing generated the following results:
- We were able to successfully communicate with the device. (see below for configuration parameters used during the testing)
- The product supported Modbus functions 3,6 & 16
The purpose of our testing is to assure a level of compatibility in the communications between the two products. Through this testing, we attempt to identify problem areas that may arise when implementing the interface in the field.
Configuration:
The product testing was performed with the following settings used:
The above configuration setup the module for Modbus Master RTU mode, with a baud rate of 9600bps, 8 data bits, 1 stop bit, and no parity.
Based on the CmdErrPtr location of 1100, the error codes for the modbus master commands were placed into MCM.ReadData[500]-[502] for Cmd[0]-[2].
The Module Definition used in our testing was as follows:
Command List:
The following command list shows some of the commands, which were used to test the communications:
Our test command list performs the following functions.
P2Cmd[0] - This command reads registers 40001-40011 and places the data from those commands in MCM.ReadData[0]-[9]. These values include the ADERROR, ERROR, PV, CSP, OUT, HOUT, COUT, MOD, PIDNO, CSPNO, and ALM parameters from the UT320.
P2Cmd[1] - Reads register 40050 and places the value for this point in MCM.ReadData[10]. This is the point D0050 from the UT320. This is one of the few points in the UT320 that can be read using a function code 3, and written to using a function code 6 or 16. The next command will write to this point inT the UT320.
P2Cmd[2] - Writes from MCM.WriteData[0] to register 40050 of the UT320. This value is then read back into the MVI56-MCM module using P2Cmd[1]. Both a function code 6 and 16 were tested for this parameter.
Cable Connection:
The physical connection that was used during testing was as follows:
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MVI56-MCM
Module
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UT320-01
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1 TXD
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Terminal 23 SDB(+)
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Terminal25 SDA(-)
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* RXD
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Terminal 24 RDB(+)
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Terminal 26 RDA(-)
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Jumper on bottom of MVI56-MCM module set for RS485 position.
Additional Comments and Observations:
Jumpers must be installed between terminals 23 and 25, as well as terminals 24 and 26 on the UT320-01 Controller.
- The UT320 only will allow for up to 64 words to be read with one function code 3 command, and only 32 words can be written with one function code 16 command.
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