USB to Serial in CitectSCADA 6.1


Thread Starter

Tibor Kubinyi

Is there anybody out there who was successful in seting up a serial link between CitectSCADA 6.1 and a Modbus PLC using a USB to RS233 converter?
I have no problem setting up the comms using the built in COM1, but I need another COM port (USB-to-RS232) to do the same. Is it at all possible? Any help will be greatly appreciated.

Nathan Slider

Your USB to Serial converter software should have a virtual COM number setting which is used. This COM number would then be Defined for your Ports Number in your Ports form. You may also need to specify a 1 in the Address section on the IODevices form as this is typically used for Modbus to Ethernet converters. Make sure you also setup your [MODBUS]InitType and [Modbus]InitUnitAddress parameters accordingly. Yes, have seen this working but not done myself.

Nathan Slider