DL06 Remote Start / Stop

[john_551]

Hello,
I have an Automation Direct DL 06 PLC and I have a problem trying to remotely start and stop the plc. I have an H0-ECOM module installed inside the PLC as well.
What I want to do is to send a string using either the Ecom or local port to switch the PLC from run to program or stop and vice versa. I know this can be done using direct soft's program, but I am interfacing to it using a linux system.
Has anyone ever caught the string that is sent from directsoft to the plc to change the state to run /prog/stop?

The reason for this, is that sometimes the rs232 ports on the computer could (very rare) get locked up. In this event I have the ability to reboot the computer, but I can not 'reboot' the PLC, in case the PLC gets locked up.

Any help would be greatly appreciated.

 

[keithkyll]

I doubt the PLC will ever lock up. That's one of the major differences between a PC and PLC based system. PLC's don't lock up.
You can have an error that can stop the program. Some are resetable, some require hardware replaement. Take a look at the internal fault table to see the various faults that can halt a PLC program.

 

[PeterW]

I doubt the PLC will ever lock up. That's one of the major differences between a PC and PLC based system. PLC's don't lock up.

I can see you have never used Momentum's then

 

[john_551]

This is so far not looking good.
I know under windows you can turn the PLC to term / prog or stop using DirectSoft.
I would like to be able to do the same thing, just using linux. Gives me more control. There has to be a string that is sent to trigger the plc in to a different mode. Wish I could get it.
John

 

[jeebusmn]

I have locked up the AD PLC 06. I was doing state programming incorrectly and it would tie up the processor enough that I couldn't even communicate with it. The plc has a super-capacitor on it to retain the code in case of power failure. I couldn't reprogram it until the capacitor discharged. Luckily, it only took a few hours and I didn't have manually discharge the capacitor.

 

[rsdoran]

DirectSoft if I am not mistaken uses the K-Sequence protocol to communicate while programming. It sounds like you expect to be able to do the same thing with an ASCII string, would surprise me if you could. One thing I expect to happen is once you put it in program mode if you could, the ASCII aspect may not work because you would be using it thru the ladder.

I am curious now though because I am not sure.

Have you attempted using Wine or ? and tried using DirectSoft with Linux?

If having issues with a PC locking up with Linux then why not use Windows, can not be any worse.

 

[geniusintraining]

I doubt the PLC will ever lock up. That's one of the major differences between a PC and PLC based system. PLC's don't lock up..

I have a DL06 thats lock up twice... just the ethernet card EDIT<--- by this I mean the rpogram was still running just not the comms

I had to reboot it, then it was fine, not sure what caused it

 

[geniusintraining]

Hello,
I have an Automation Direct DL 06 PLC and I have a problem trying to remotely start and stop the plc. I have an H0-ECOM module installed inside the PLC as well.
What I want to do is to send a string using either the Ecom or local port to switch the PLC from run to program or stop and vice versa. I know this can be done using direct soft's program, but I am interfacing to it using a linux system.
Has anyone ever caught the string that is sent from directsoft to the plc to change the state to run /prog/stop?

The reason for this, is that sometimes the rs232 ports on the computer could (very rare) get locked up. In this event I have the ability to reboot the computer, but I can not 'reboot' the PLC, in case the PLC gets locked up.

Any help would be greatly appreciated.

If the PLC is lock you can not send a string or anything... the only thing you can do is power down then back on

Your Ethernet will not work either nor will your direct port, as I said that has been my experience

 

[john_551]

Have you attempted using Wine or ? and tried using DirectSoft with Linux?

I have tried using wine and with directsoft. Not a very good mix to say the least, doesn't work!

If having issues with a PC locking up with Linux then why not use Windows, can not be any worse.

The unit that is physically connected is a Linux system not a windows system. My configuration talks with the plc regularly. So using a windows system is out of the question.

DirectSoft if I am not mistaken uses the K-Sequence protocol to communicate while programming. It sounds like you expect to be able to do the same thing with an ASCII string, would surprise me if you could. One thing I expect to happen is once you put it in program mode if you could, the ASCII aspect may not work because you would be using it thru the ladder.

When you use Directsoft, you can switch between term / prog / run with a simple mouse click. What I would like to be able to do is that same thing in linux. Be able for my cmputer to issue the same string that directsoft uses over the ethernet to change the dl06 to a different mode.

 

[john_551]

The reason I am wanting to do this is so that if the computer's com port does get screwed up, I can reboot the computer and clear the com port and then issue a run command. It is so that the computer and plc are in 'sync'.
If the computer's com port does get screwed up and I reboot the computer, I don't want the plc waiting in the wrong spot of the program. It would make it much easier to 'restart' the plc to be in sync with the computer.

 

[bernie_carlton]

Restarting a PLC, without any other safety controls, could start a machine in an unsafe manner (people standing around wondering why the machine isn't running etc then the machine suddenly starts). I think any restart of a PLC should be a local function only.

 

[john_551]

Restarting a PLC, without any other safety controls, could start a machine in an unsafe manner (people standing around wondering why the machine isn't running etc then the machine suddenly starts). I think any restart of a PLC should be a local function only.

The machine that is restarting is an unattanded kiosk. Nobody is around, near or inside the machine. I sometimes restart my machines for many different types of reasons. Also it's kind of hard to make it a local thing when I am located 3000 miles away!

 

[rsdoran]

You would need to talk to AD I think, the programming software and handheld programmers may have access to internal control/status bits that are not offered through programming.

If there is no safety hazard then maybe something could be controlled by the PC to just recycle power to the plc after the PC reboots. May want to have a "handshake" between them to establish everything comm wise is ready to go.

 

[consys]

Some Modem manufacturers offer digital I/O on the modem, if you do not have any luck with restarting the PLC via software maybe you can tell the modem to cycle power to the PLC.

 

[Steve Bailey]

The details of how to use DirectNet protocol for PLC communications have been available for many years under several different names. The same protocol can be used to transfer ladder programs, but they don't publish the details of how to do that. The same is true of the details of how to start/stop the execution of the program.

If the computer's com port does get screwed up and I reboot the computer, I don't want the plc waiting in the wrong spot of the program

From this comment I gather you are running a stage program rather than ladder logic, since ladder doesn't "wait" in any particular spot. Instead of trying to reverse engineer the protocol to figure out how to restart the PLC, why not include a reset function in the program that drives it to a specific stage. Trigger the reset by a change in the value in a V memory location. When you reboot the computer you could run an application that establishes communication with the PLC, reads the V memory value and increments it by one.

I'm not an expert in Linux, but there are examples in the DirectNet manual that show how to read and write to V memory. I expect they can be adapted to run under Linux. Download the file dadnet.pdf from the Automation Direct website.