Created Date: September 20,2007

Created by: HMI PM

Adjusting the communications timeouts to compensate for errors is often a sign that there are problems with the cable connection (often grounding) or interference from other devices. Is it possible that when this phase of the machine cycle is active, there are devices that are causing electrical noise when activated? (Stepper modules, drives or similar)

Is it possible to try a dry run of the application without some of the devices connected? If it functions fine, you may be able to then determine if it is noise that is effecting your C-more communications.

Created Date: September 20,2007

Created by: teritask

How long has the CMore been in service? I ask because I was using one that would periodically display that message even though I know there was no communication issues (grounding correct, values set correctly). Eventually the message would appear constantly, followed by total lock-up. Then, the light on the back began blinking red indicating no operating system and the screen would only display "Loading... ". I have since had the unit replaced and have not received the communication error once...same PLC, same power supplies, etc. I'd keep an eye on it.

Created Date: September 20,2007

Created by: dripsys

The communication is working fine when the servo motor is not turning. Only when the process starts and the motor is running, I receive communication interruption. My logic is that since the drive handles the motion profile it has less time to handle the communication, hence the interruptions.

However, I also had some suspicions that the problem may come from noise induced by the motor/drive (the only devices running). So today I made a new cable with a good shield. I connected the shield only on the drive side and not on the C-More side, (is this correct?) I was hoping that it will solve the problem; however the problem remains. Next I checked the website and noticed that there is a small software/firmware update from build 07.32 to 07.35. It also mentioned that the DH-485 communication timing was optimized. I am not sure what the DH-485 is, but it made me think maybe I should switch the communication from RS-232 to RS-485, even though the distance is less than 2 meters (6 ft). Once I did that, the problem disappeared. I am wondering what actually caused the problem, noise, communication protocol, firmware upgrade, etc.

Any thoughts?

Thanks.

Created Date: September 19,2007

Created by: dripsys

I am connecting a 6� C-more panel to a servo drive using Modicon RTU-Modbus.

The servo drive is going through 350 cycles per minute and I have an animation on the panel that advances with each cycle. When the screen loses communication with the drive the animation stops and an error message appears at the top (PLC-001: PLC Communication Timeout).

I am trying to not display the message at the top at all, but Tech Support told me that there is no way of not displaying the error. Does someone know of a way to switch this error displaying off?

I also tried to play with the Timeout time in the Panel-Manager. When I set the Timeout to 1 (100 ms) I could see that the animation could follow nicely and didn’t miss any cycles although it was delayed sometimes. When I increased the Timeout to 30 (3000 ms = 3 sec) things got worse. When the communication was lost, the animation was frozen for the duration of the Timeout.

The manual states that the panel will not display the error unless the communication was lost for the entire Timeout time, but it seems to work differently. Any idea?

I can live with the Panel losing communication periodically, but it is annoying to get the message at the top and confusing to the operator.

Any suggestions are appreciated.

Thanks