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Messages - hemiguy

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1
Technical support / alternating on off leds
« on: August 08, 2012, 07:59:47 AM »
Hi.
I am using a Nano-10 for led illumination on a vision system. I have a pot on each of the the two two analog inputs to vary the intensity,  then alternately turn on/off the two PWM outputs to create alternate flashing banks of leds. I'm using a .01s clock on each line for timing. Custom functions control the input and output.

Its working ok, but now I want to use a couple of digital inputs to change the timing for high medium low flash rate.
I'm not sure how to go about it.  I could add another line with a different clock rate, but they would all count as it goes through each loop.
My attempts at using timers have not been good. Does anyone have a suggestion?
Thanks,
John


2
Technical support / Re:Corrupted response from PLC
« on: April 13, 2009, 01:27:53 PM »
Ok, I'll give it a try and let you know.

Thanks,
J

3
Technical support / Re:Corrupted response from PLC
« on: April 13, 2009, 12:39:29 PM »
Hi, thanks for the quick reply.

Yes I have the PLC source, I will have to examine it, I do see a netcmd$, and we update EEprom, but I'm not sure how often.
I'm not very familiar with ladder logic yet.  


We use SendCommand from VB:
Private Sub UpdateWatchDog()
        SendCommand("Wb041AFF")

Looks like there is a 5 second timeout.
Dim timeLock As Haack.Threading.TimedLock = Haack.Threading.TimedLock.Lock(sendCommandLock, TimeSpan.FromSeconds(5))


This problem occurs also when the tool is idle. I can log all serial activity on the PC over time, so I know what's going on, but is there a tool to monitor and log what's going on in the PLC at the same time so I could correlate between the two, especially when idle?

Thanks,
John

4
Technical support / Re:Corrupted response from PLC
« on: April 13, 2009, 11:00:29 AM »
Hi.
I'm working on this project now and we are still having this problem.
To answer your questions:

Are you using a built-in serial port or USB-to-RS232 converter? If it is the latter what brand of converter are you using?
Two serial ports, one built in and an additional serial card installed in the pc.

Are you connected to the PLC via RS232 or RS485 port? Is it one PC to one PLC?
Rs232, one pc, two plcs.

What programming language are you using to handle the communication?
Visual basic 2003.

Did you try to run TRiLOGI and TLServer to monitor the PLC and do you observe any communication error?
Not sure what you mean.

I added some logging to capture the communication and it appears to be completely random. Both Plcs will simply send a bad character, or send nothing. We retry the command up to three times and usually it recovers, but sometimes not and we lose communication. I've tried different baud rates, electrical filtering, which helps a bit, but the problem is still there.
I delayed updating the watchdog (Sleep(200)) as its updated continually, which did not help.
Our customers are seeing failures often as they run 24x7.
I'm out of ideas!

Thanks,
John

Here are some examples:
4/6/09 13:52:41   PLC2 retry, response = @01Wbw4*
4/6/09 13:52:41   Command sent was: Wb041AFF
4/7/09 17:30:49   PLC2 retry, response =
4/7/09 17:30:49   Command sent was: WR0400

4/7/09 18:41:37   PLC1 retry, response = @01Wbw4*
4/7/09 18:41:37   Command sent was: Wb040CFF

This is a sequence where the system failed:
4/8/09 05:04:21   PLC1 retry, response =
4/8/09 05:04:21   Command sent was: WR0400
4/8/09 05:04:21   PLC2 retry, response =
4/8/09 05:04:21   Command sent was: Wb041AFF
4/8/09 05:04:22   PLC1 retry, response =
4/8/09 05:04:22   Command sent was: WR0400
4/8/09 05:04:22   PLC2 retry, response =
4/8/09 05:04:22   Command sent was: Wb041AFF
4/8/09 05:04:23   PLC1 retry, response =
4/8/09 05:04:23   Command sent was: WR0400
4/8/09 05:04:23   PLC2 retry, response =
4/8/09 05:04:23   Command sent was: Wb041AFF
4/8/09 05:04:24   PLC1 retry, response =
4/8/09 05:04:24   Command sent was: WR0400
4/8/09 05:04:24   Connection to PLC1 lost.
4/8/09 05:04:24   PLC2 retry, response =
4/8/09 05:04:24   Command sent was: Wb041AFF
4/8/09 05:04:24   Connection to PLC2 lost.




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