Good morning,
I need to communicate with a device through Modbus using a port on the cRIO NI 9871 module. I would like to use a Modbus I/O Server to simplify the programming. I'm currently trying to test communications but I'm having trouble with passing data from master-->slave or slave-->master. Here is a summary of the setup:
cRIO 9030 with NI 9871 in slot 4
cRIO 9035 with NI 9871 in slot 2
I can write data using VISA test panels in NI Max so I know the serial ports see each other.
I've created a Modbus I/O Server on each cRIO. cRIO 9030 is a slave server and cRIO 9035 is a master server. My test VIs are extremely simple, I just write to a coil on one server and read the same coil on the other, just to test if data is getting through. I can't get any communication. When I try to configure each I/O server for Modbus serial, it provides a serial port menu that lists COM1 through COM32. I don't know how to find what these COM ports map to. I think my problem may be related to which COM port is setup in the server settings.
I found the following article to create the server programmatically, but I can't find this option in my version of Labview (2015).
http://zone.ni.com/reference/en-XX/help/371618K-01/lvdsc/dsc_create_config_io_server/
Any ideas? Thanks