MicroLogix 1200 communication to laptop

[thebard3]

All,
At a customer site yesterday, they have several MicroLogix 1200 controllers. Some of the controllers have 2 communication ports, 2 of them have only one on the front. Using RSLinx Classic and a PM02 (series B) cable, I was able to connect to each of the ports on the controllers with 2 ports. They both appear as DH485 protocol. I was unable to establish communication with the controllers that have only one port. I attempted deleting the driver and recreating it numerous times, and get a timeout message using autoconfigure. As I had no trouble connecting to the controllers with 2 ports, I know I am using the correct cable and the correct port configuration, unless I need a different cable for the (presumably) older controllers. Any ideas?

Brad Waybright

It's all okay as long as it's okay.

 

[controlsdude]

It can depend on your rslinx version too. Maybe your rslinx version is not recent enough. But since its older controllers maybe there is a different driver selection that you need to use.

 

[thebard3]

Thanks controlsdude, but I learned that lesson the hard way. I always keep the latest version of LINX. I just can't imagine what is different about the ports on the 2 controllers.

Brad Waybright

It's all okay as long as it's okay.

 

[catserveng]

Single port MicroLogix controllers can be set for multiple protocols, usually DH485 or DF1, Processors with the second port, the Program/HMI port only supports DF1 comms, with fixed baud rate and other parameters

A PM-02 cable is a RS232 cable for DF1 comms, if the port is set for DH485, then you need a converter, like a 1747-PIC (serial) or UIC (USB), there are also some aftermarket DH485 comm adaptors that work quite well too.

If the single port ML1200 will not communicate with your laptop and a serial cable, it may be setup for DH485, in that case you can press and hold the DCOMM button under the cover, and the comms will revert to the default DF1 setup for the port, this link discuss's the issue,

https://control.com/thread/1342907356

MikeL.

 

[thebard3]

Thanks, Mike. I searched that forum and didn't find that post. I missed part of the port configuration, when I auto-configured and connected to the 2-port units, the driver showed up as DH-1 RS485 which I thought was wierd. Also didn't know about the DCOMM button. I was there after hours and didn't have internet access either. Unfortunately the jobsite is 200 miles from me so it's not something I can go back and test. I think our customer is going to buy the 2 port controllers anyway, as we are replacing the old PanelView HMIs with PanelView Plus, and with a single port it's necessary to disconnect the HMI to work on the machine. With the new controller and HMI they'll have 6 identical machines.

I appreciate the help.

Brad Waybright

It's all okay as long as it's okay.

 

[thebard3]

Revisited the site yesterday. The DCOM button worked perfectly and I was able to swap out 2 old panelviews on DH485 with PVPlus on DF1

Brad Waybright

It's all okay as long as it's okay.