Modbus TCP for HC900 C70

I am currently working on a steam generation plant.
We are using Honeywell HC900 C70 controller.
There are 30+ instruments connected to E&H memograph and i am trying to read the value using modbus tcp slave block but no results.
Any suggestions.

If you are using the HC900 Modbus Slave Function Block (FB), then the HC900 is the Modbus Master/client who reads from the E&H recorder which is a Slave/server using the MBS and MBR Function Blocks.

Assuming you want to read the values from the recorder, then each RDn position on the right side of MBS1xx FB or the MBR1xx Modbus Read FB must be "tagged" with a tag name and the tag configured to read register nnnnn (hexadecimal addressing, zero based) and have the correct Function code associated with the register in the recorder, as shown in the screen shot of the properties of the MBR FB.

In the attached file, Slide #22 (page 1, bottom, pdf) "Modbus Master Interface - Serial" summarizes the Modbus master function, which is the same for Ethernet/TCP as it is for serial, other than the serial configuration required on the HC900 COM port. Yes, I know you're doing Ethernet, but the setup of the Modbus functions are the same, only the COM port varies. Obviously, the register addressing is different for the E&H than it is for the Honeywell in the example.

Assuming you want to read the values from the recorder, then each RDn position on the right side of MBS1xx FB or the MBR1xx Modbus Read FB must be "tagged" with a tag name and the tag configured to read register nnnnn (hexadecimal addressing, zero based) and have the correct Function code associated with the register in the recorder, as shown in the screen shot of the properties of the MBR FB.

I always word at getting just one or two points read and displayed before moving onto all the configuration for the remaining points.

My bad. You're correct in using TCPS function block. Slightly different setup than the RTU serial MBS FB, but the same basic concept.

thanks for your time.

Does HC900 C70 supports Modbus master and slave on the same port.
This is because some of my field devices are Modbus Master and some are modbus slave.I can't separate the network and use the second port in HC900 C70

Modbus/TCP Client (Master) and server (slave) are avaiable through either E1 or E2 Ethernet ports.




For the port allocation for Modbus RTU (Serial) master/slave, see the attached single page pdf.

Danw, get's the MVP award for this thread! Very useful. Thanks!