Created Date: May 28,2016

Created by: Nez

Hi all, I'm hoping someone can help me. I just joined a company where the lead engineer left and didn't leave any documentation of their work. I have never done any PLC programming, so I'm hoping I know enough now (after reading up on it since Tuesday) to ask meaningful questions.

We tried to get the linear guide working in our system (to go back and forth in a certain pattern), but it moved differently every time the motion program was activated (via HMI and PLC code). We have an Automation Direct system with a P3-550 CPU running with P2000 code. The motor drive, STP-DRV-80100, is connected to a stepper motor, STP-MTRH-23079. We plug the drive into the RS-232 port in the CPU.

Here are things we know:

The drive is communicating with the PLC, because we do get motion of the motor/linear guide.

For another system we built, the exact same PLC and HMI code functions properly , with the linear guide moving in the expected pattern every time the motion program is started (this system is in Taiwan and not easily accessible).

The wiring between the motor and drive is correct.

The cable connecting the drive to the CPU is functional.

The drive can connect to a laptop via SureStep and passes the Self Test, but will not upload settings because of a "communication error ".

We decided to try a new drive of the same model. It can also connect to the laptop via SureStep, passes the self test and can upload its settings! (progress!) It can be controlled using the SCL command box, but when we connect it to the PCU and start the motion program, the motor does not move. The drive displays a comm error. Interestingly, the PLC code must be running because a counter on the HMI displays the number of moves completed.

Can anyone help figure out what is going on? I think the new drive is not configured properly and is therefore not accepting the PLC commands, but I don't know what the correct configuration is, nor how to go about determining what the correct config is. I have looked at the PLC code and the ASCII strings being fed into the drive and the syntax of the SCL seems fine. I can post the code if that would help.

I'm really nearing the end of my patience with this thing and I am concerned I'm going to have to dig in and spend weeks learning ladder logic, PLC programming and SCL programming. The entire start-up is being held back because we can't get the sassafrassin LINEAR GUIDE TO RUN!

Thanks in advance-

Nez

Created Date: May 28,2016

Created by: plcnut

I don't have very much to add, but I can tell you that the problem with your old drive is because the transmitter for the rs232 has been burned up. This can happen when you use the wrong cable and plug it into a PLC that has a 5 volt power supply for an HMI. You can replace the communications chip which will allow you to recover the configuration from the drive. It will require removing the circuit board from the case, getting the numbers from the chip, getting a replacement, and then desoldering the old one, and soldering in the new.