Communication with i-7018

[redpike]

I am having difficulty establishing communications with my i-7018. I have a USB to RS-232 adapter, designated com port 6. I have established communication with the T100MD-888+, but keep getting an "Open COM6 error!". I tried resetting the PLC and computer baud rates at 9600, still able to maintain communications between PLC and computer, but same error with DCON Utility when trying to find the i-7018.

Any help?

[support]

Is your difficulty between the PC and the I-7018? I don't suppose you have communication between the T100MD+PLC and I-7018?

When you run TLServer, then TLServer has opened com port 6 and it is no longer available to DCON. You will have to close the port on TLServer or quite TLServer altogther before you run the DCON utility in order to use COM6.  I hope this is the cause of your problem and this would resolve it.

[redpike]

Okay, that worked to get access to the port, but there still seems to be no communication with the i-7018. Do I need to reset the baud rate for the T100MD and PC to 9600? Does the i-7018 require a terminating resistor, or is it internally terminated?

I am trying to communicate with the i-7018 via the PLCs RS485 connection, by using an RS232 connection from the PC to the PLC.

[support]

You can't do that.

The PLC is not a RS232 to RS485 converter. You can't use DCON to talk to the PLC's RS232 port while its RS485 port is connected to the I-70xx. The PLC's RS232 port and RS485 port are two independent ports under control by the PLC's CPU. Hence unless you write a special program inside the PLC specifically to perform the task of taking the data from its RS232 port and send out to RS485 port and vice versa, whatever you send to the PLC stops in the PLC and doesn't get passed to its RS485 port.  

In order to use DCON on a PC to talk to the I-70xx directly, you have to use an RS232 to RS485 converter (e.g. Auto485  http://www.tri-plc.com/auto485.htm) to connect the PC's RS232 port to the I-70xx RS485 port and then it should work.

[redpike]

Okay, so what I need to do, if I'm communicating with the PLC via RS232, and from the PLC to the i-7018 via RS485, is download a program to the PLC which communicates with the i-7018--and then execute that program.

I will eventually be connecting two i-7018 devices to the PLC, can I change the default ID for the second i-7018 via a program sent to the PLC, or do I need to directly communicate with the i-7018 via an RS485 connection to the PC?

[support]

Yes, you need to write a PLC program to talk to the I-70xx. There are sample programs in the following folder that you can follow:

C:\TRiLOGI\TL5\usr\samples\I-7000

It is always much easier to use the DCON utility to directly configure the I-70xx on a PC since you have visibility of what's going on and the result of your changes is confirmed visually on the PC. After you have configured the I-70xx including setting its ID, then connect the I-70xx to the PLC so that the PLC can perform data acquisition from the I-70xx modules.

[Dogface]

I'm currently working on a project using the M-7024 and M-7018.  The most versatile method I've found for doing what you are attempting, is to use a RS232 to RS485 adapter with the PLC and the Input module(s) all on the same twisted pair.  You can plug your computer into the adapter and communicate with either the PLC or with the 7018.  You will not be able to communicate with them simultaneously.  Either TL server or the DCON utility must be running, not both.  I left the converter inside the cabinet for ease of troubleshooting in the future.  This also leaves the RS232 port of the PLC open for future growth, ie... HMI, Internet, Printer....
Also, you will get lot's of errors using DCON(master) if the PLC(master) is trying to communicate with the I-7018.  There are numerous ways to overcome this problem.
A simple DPST toggle switch can be used to isolate the PLC from the rest of the network while you are using DCON.  Power off the PLC.  Activate an input that will halt PLC communication.... many ways.  Activating an input is probably the cleanest method.
Hope this helps.

Dogface