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Technical support / Re:PLC to PLC Comm Stopped Working
« on: February 22, 2014, 01:22:35 PM »
Replaced the IC - everything is working fine now. Thanks for the help and advice.
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Technical support / Re:PLC to PLC Comm Stopped Working
« on: February 16, 2014, 12:38:27 PM »
Hi, thanks for the quick reply.
Yes, the PC and Putty are set to 38400,8,n,1. When I power cycle the FMD with DIP Switch#4 ON, I get the same gibberish on the comm monitoring program (Putty). Still cannot get a response on TLServer to IR* command. Same "Warning: No Response from PLC"
Yes, I had some testing code I forgot about in the T100MD+ that was sending out modbus traffic on COMM3. I removed the code and confirmed no communication was being sent with Putty. I power cycled the T100MD+ with DIP Switch #4 ON, Still cannot get a response on TLServer to IR* command. Same "Warning: No Response from PLC"
The FMD was acting as the master, using the READMODIBUS and WRITEMODBUS commands to manipulate and read inputs on the T100MD.
Yes, the PC and Putty are set to 38400,8,n,1. When I power cycle the FMD with DIP Switch#4 ON, I get the same gibberish on the comm monitoring program (Putty). Still cannot get a response on TLServer to IR* command. Same "Warning: No Response from PLC"
Yes, I had some testing code I forgot about in the T100MD+ that was sending out modbus traffic on COMM3. I removed the code and confirmed no communication was being sent with Putty. I power cycled the T100MD+ with DIP Switch #4 ON, Still cannot get a response on TLServer to IR* command. Same "Warning: No Response from PLC"
The FMD was acting as the master, using the READMODIBUS and WRITEMODBUS commands to manipulate and read inputs on the T100MD.
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Technical support / Re:PLC to PLC Comm Stopped Working
« on: February 16, 2014, 08:20:13 AM »
Thank you for the advice. I used the USB-RS485 adapter to attempt direct communication with each PLC and to monitor RS-485 network traffic. Using the TL Server app, and connecting directly between the PLC and RS-485 USB adapter, I was not able to communicate with either PLC. The "IR*" command returned "(Warning: No Response from PLC!)" This happened on both the older T100MD and the new FMD-10.
So, following your advice I networked them together and used Putty to monitor the network activity. See attached text file. With both PLC's attached, the traffic was all over the place. When I disconnected the FMD-10, and left the T100MD connected, the traffic seemed to follow a more uniform, repeating pattern.
This is my first experience in reviewing 485 traffic, so I really don't know what I'm looking at, but I would guess the FMD-10 485 driver is faulty.
Looking forward to your feedback, thanks again.
So, following your advice I networked them together and used Putty to monitor the network activity. See attached text file. With both PLC's attached, the traffic was all over the place. When I disconnected the FMD-10, and left the T100MD connected, the traffic seemed to follow a more uniform, repeating pattern.
This is my first experience in reviewing 485 traffic, so I really don't know what I'm looking at, but I would guess the FMD-10 485 driver is faulty.
Looking forward to your feedback, thanks again.
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Technical support / PLC to PLC Comm Stopped Working
« on: February 08, 2014, 01:02:11 PM »
Hi -
I've been using RS-485 to communicate between two PLC's. Basically, I ran out of Outputs on my FMD-10 PLC and used the RS-485 port to write outputs to my old T100MD. It's a straight run of about 4' of twisted pair between each 485 port. In a 1 second scan on the FMD, I have the following code:
WRITEMODBUS 13,1,16, OUTPUT[1]
RELAY[5] = READMODBUS(13,1,0)
My FMD-10 is ID#3, and my slave is ID#1. There is no comm code running on the slave. I'm not using a SETBAUD command either. This has been working fine for months, until I added an additional Output on the slave PLC today. Once I power cycled the slave PLC, the comms stopped working all together. I tried using the SETBAUD command to ensure the baud rates were the same on each PLC. No luck.
I've also tried changing ID's, reading different registers, etc. It just seems like the comm port stopped working.
Both PLC's run their intendant programs without issue. Again, it's been working for months and the only thing I did today was add another output relay on the slave PLC.
I've been reading forums and reference material all day, I'm at a lose. Any feedback would be appreciated.
I've been using RS-485 to communicate between two PLC's. Basically, I ran out of Outputs on my FMD-10 PLC and used the RS-485 port to write outputs to my old T100MD. It's a straight run of about 4' of twisted pair between each 485 port. In a 1 second scan on the FMD, I have the following code:
WRITEMODBUS 13,1,16, OUTPUT[1]
RELAY[5] = READMODBUS(13,1,0)
My FMD-10 is ID#3, and my slave is ID#1. There is no comm code running on the slave. I'm not using a SETBAUD command either. This has been working fine for months, until I added an additional Output on the slave PLC today. Once I power cycled the slave PLC, the comms stopped working all together. I tried using the SETBAUD command to ensure the baud rates were the same on each PLC. No luck.
I've also tried changing ID's, reading different registers, etc. It just seems like the comm port stopped working.
Both PLC's run their intendant programs without issue. Again, it's been working for months and the only thing I did today was add another output relay on the slave PLC.
I've been reading forums and reference material all day, I'm at a lose. Any feedback would be appreciated.
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Technical support / Re:Pump Seq
« on: February 28, 2012, 04:56:36 AM »
Eureka!
I found the error in my ways. The ladder logic I was using initially was near identical to what you had suggested, so I stepped back from the trees to see the forest.
I had a .5 clock that triggered a custom function to update all of the variables read by my HMI software. In that custfunc, I was updating the Set Timer SV value. So every ? second the timer was getting updated, causing the fluctuating results.
My new plan is add the update SV command in each timer. This way the active timer would update the inactive timer.
THANK YOU!!
I found the error in my ways. The ladder logic I was using initially was near identical to what you had suggested, so I stepped back from the trees to see the forest.
I had a .5 clock that triggered a custom function to update all of the variables read by my HMI software. In that custfunc, I was updating the Set Timer SV value. So every ? second the timer was getting updated, causing the fluctuating results.
My new plan is add the update SV command in each timer. This way the active timer would update the inactive timer.
THANK YOU!!
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Technical support / Re:Pump Seq
« on: February 27, 2012, 05:39:11 AM »
Hi Gary,
Thanks for the reply. I'm using a T100MD+r49 PLC. My first attempt was to use two lines of ladder logic. The first line closed the output and starts timer1.
When timer1 expires, it starts timer2 on the second line, which opens the circuit on the first line (killing the timer and opening the output). When the second timer expires, it re-initiates the timer1 and the process starts over again.
Timer1 serves as my "on time" and timer2 serves as my "off time". The timers are set to the same interval (50% duty cycle). While this was running, I noticed a significant performance impact on the PLC.
I also tried using a sequencer with similar results:
Observing the Output LED while the process was running, I see a very rapid double-blink, then off for the appropriate duration, back on (double-blink again), then solid for the appropriate duration, etc
I sorry if I'm not explaining it very well ? but I expected to see a smooth on/off pattern and I'm not getting that.
The pump being commanded needs to be accurate within 500ms. I double checked my code, I am using the SV command (not PV).
I feel like I'm missing something obvious.
Thanks for the reply. I'm using a T100MD+r49 PLC. My first attempt was to use two lines of ladder logic. The first line closed the output and starts timer1.
When timer1 expires, it starts timer2 on the second line, which opens the circuit on the first line (killing the timer and opening the output). When the second timer expires, it re-initiates the timer1 and the process starts over again.
Timer1 serves as my "on time" and timer2 serves as my "off time". The timers are set to the same interval (50% duty cycle). While this was running, I noticed a significant performance impact on the PLC.
I also tried using a sequencer with similar results:
Observing the Output LED while the process was running, I see a very rapid double-blink, then off for the appropriate duration, back on (double-blink again), then solid for the appropriate duration, etc
I sorry if I'm not explaining it very well ? but I expected to see a smooth on/off pattern and I'm not getting that.
The pump being commanded needs to be accurate within 500ms. I double checked my code, I am using the SV command (not PV).
I feel like I'm missing something obvious.
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Technical support / Pump Seq
« on: February 26, 2012, 06:00:40 AM »
Hello - I need to cycle a small pump on and off at intervals defined by the operator.
I tried using two timers to alternate on/off and the PV command. I have no issues changing the PV value of the timers, however the results are inconsistent, meaning the output does not cycle on and off in a precise manner.
The cycle time is between 1 and 5 seconds and I?m using a regular timer. Should I try using a high speed timer?
What is the best way to accomplish this?
Thanks in advance.
I tried using two timers to alternate on/off and the PV command. I have no issues changing the PV value of the timers, however the results are inconsistent, meaning the output does not cycle on and off in a precise manner.
The cycle time is between 1 and 5 seconds and I?m using a regular timer. Should I try using a high speed timer?
What is the best way to accomplish this?
Thanks in advance.
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Technical support / Re:PWM Control
« on: April 04, 2011, 06:56:26 AM »
It's definitely looking for PWM. Thanks for the advice; I'll use a voltage divider and diode.
Thanks again.
Rob
Thanks again.
Rob
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Technical support / PWM Control
« on: April 03, 2011, 11:53:57 AM »
Hi,
I plan on using my T100MD PWM output to control a Meanwell Dimmable LED power supply.
The MW PS is looking for a Full PWM Voltage of 10V. What is common practice here? Should a supply 10V to the MWPS using a seperate PS or voltage divider? Or use the 24V and limit the duty cycle to 41%?
Thanks,
Rob
I plan on using my T100MD PWM output to control a Meanwell Dimmable LED power supply.
The MW PS is looking for a Full PWM Voltage of 10V. What is common practice here? Should a supply 10V to the MWPS using a seperate PS or voltage divider? Or use the 24V and limit the duty cycle to 41%?
Thanks,
Rob
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Technical support / Re:Analog Input self incrementing
« on: March 27, 2011, 10:22:28 AM »
Thanks for the quick reply. I'm a dummy, you are correct, I was looking at the wrong channel.
Thanks again.
Rob
Thanks again.
Rob
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Technical support / Analog Input self incrementing
« on: March 27, 2011, 10:11:33 AM »
I have a T100MD888 with an iSnail 0-5VDC CT. I have the positive terminal of the CT connected to AD Pin #5. The Negitive terminal is connected AD Ground.
There is a steady 2V reading on the terminals of the CT.
I have a 1 second clock circuit that updates the ADC(5) reading. When the PLC restarts, the reading starts near zero and increaments by 8 until it reaches 4096.
What am I doing wrong?
There is a steady 2V reading on the terminals of the CT.
I have a 1 second clock circuit that updates the ADC(5) reading. When the PLC restarts, the reading starts near zero and increaments by 8 until it reaches 4096.
What am I doing wrong?
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