Is it possible to control this display with programmable logic controller? I made a simple program with CX-programmer to Omron CJ1M just to send a few symbols. Windows terminal (not hyper terminal) show those symbols correctly, but nothing on display. Do I need any kind of start and/or end marks when sending data from PLC to display? Baud rate settings are correct and I've tried all formats from 7,1,E to 8,2,N. I can send from PLC to Windows terminal program and from there to display, but not from PLC straight to display. If you have any idea what I'm talking about please let me know and I can try to explain more.
Thank you.
LK204-25 and PLC
Hello Troy,
thank you for your reply.
I changed the settings as you recommended. I also made one important change to the cable. PLC program is now sending clear screen command in every second. Display just doesn't clear, but it's blinking in every second so something is going from PLC to the display. It looks like it's refreshing the display.
thank you for your reply.
I changed the settings as you recommended. I also made one important change to the cable. PLC program is now sending clear screen command in every second. Display just doesn't clear, but it's blinking in every second so something is going from PLC to the display. It looks like it's refreshing the display.
Kymppi
Hi Kymppi,
Good to hear you've got some improvement, although still no proper functionality. To start, I'd recommend sticking to character transmission, it's just a little easier to tell if it is successful. Also, make sure your PLC and display are communicating at the same levels. By default the display is expecting RS232 levels, your controller may be sending TTL levels. You can change the default on the display if necessary by moving the protocol jumpers as indicated in the manual.
~Troy
Good to hear you've got some improvement, although still no proper functionality. To start, I'd recommend sticking to character transmission, it's just a little easier to tell if it is successful. Also, make sure your PLC and display are communicating at the same levels. By default the display is expecting RS232 levels, your controller may be sending TTL levels. You can change the default on the display if necessary by moving the protocol jumpers as indicated in the manual.
~Troy
Troy Clark
Design & Development
Matrix Orbital
Design & Development
Matrix Orbital
Hello Troy,
yes some improvement happened and I believe it's very close to succeed.
You mentioned character transmission and I was ment to ask you something about it. I can set start and end codes in PLC port settings. Do I need any? In manual there is many commands that start 0xFE so I tried to put this 0xFE to start code and then send some characters, but it didn't work. Still I don't have any end code to test and it's a little bit too big job to try every code.
One guy who knows a lot this programming told me to try change the order of commands. I mean to write for example clear screen 0xFE 0x58 command as 0x58 0xFE or FE58 or 58FE or 0x58 0xFE, but none of these is working. Then he asked what is that little "x". There is no x in hexadecimal. I'm not that good in programming so I just told him that it could be replaced with an zero and so we've been doing. Is it right?
PLC is sending RS232 levels. Btw the port mode is RS232C, could this bring some problems?
yes some improvement happened and I believe it's very close to succeed.
You mentioned character transmission and I was ment to ask you something about it. I can set start and end codes in PLC port settings. Do I need any? In manual there is many commands that start 0xFE so I tried to put this 0xFE to start code and then send some characters, but it didn't work. Still I don't have any end code to test and it's a little bit too big job to try every code.
One guy who knows a lot this programming told me to try change the order of commands. I mean to write for example clear screen 0xFE 0x58 command as 0x58 0xFE or FE58 or 58FE or 0x58 0xFE, but none of these is working. Then he asked what is that little "x". There is no x in hexadecimal. I'm not that good in programming so I just told him that it could be replaced with an zero and so we've been doing. Is it right?
PLC is sending RS232 levels. Btw the port mode is RS232C, could this bring some problems?
Kymppi
Hi Kymppi,
They'll be no start or end codes for the display, just the data listed. The '0x' at the beginning of the command bytes is just there to denote a hex value, it is not to be transmitted. Just make sure the data is sent in hex and you'll be fine.
As for the RS232C, that should be fine as I'm not aware of any difference between that protocol and what we call RS232.
Try taking out those start and end codes and let me know if there is any improvement.
Thanks,
~Troy
They'll be no start or end codes for the display, just the data listed. The '0x' at the beginning of the command bytes is just there to denote a hex value, it is not to be transmitted. Just make sure the data is sent in hex and you'll be fine.
As for the RS232C, that should be fine as I'm not aware of any difference between that protocol and what we call RS232.
Try taking out those start and end codes and let me know if there is any improvement.
Thanks,
~Troy
Troy Clark
Design & Development
Matrix Orbital
Design & Development
Matrix Orbital
Hey Troy,
I've tried it without start and/or end codes, but still not working. There is now TxD block in PLC program that sends data from memory address D1000 and in D1000 there is 0061 0061 0061 in hex so I guess there should be "aaa" in the display, but it says "Matrix Orbital LK204-25". This display works fine with PC. I tried that too. I can now see why so many use these as an extra display when modding cases etc.
I'm pretty positive that PLC sends the data without any conversions what so ever, like the manual says, but I'll contact to PLC manufacturer and ask what it sends and how. You'll be first to know what they say.
Yeah, I was remembering something like that about the "0x", but I wasn't sure.
I've tried it without start and/or end codes, but still not working. There is now TxD block in PLC program that sends data from memory address D1000 and in D1000 there is 0061 0061 0061 in hex so I guess there should be "aaa" in the display, but it says "Matrix Orbital LK204-25". This display works fine with PC. I tried that too. I can now see why so many use these as an extra display when modding cases etc.
I'm pretty positive that PLC sends the data without any conversions what so ever, like the manual says, but I'll contact to PLC manufacturer and ask what it sends and how. You'll be first to know what they say.
Yeah, I was remembering something like that about the "0x", but I wasn't sure.
Kymppi
Hi Kymppi,
Good to see your enjoying the display, we've actually gone a little more advanced with some of our newer displays for the purpose of PC modding because so many people seem to use them.
As for communication, you may want to run your lines through an oscilloscope, just to see what's coming through. Also, a quick wiring note, Tx from your controller will go to Tx on your display. The labeling can be a little confusing so the lines could be reversed.
~Troy
Good to see your enjoying the display, we've actually gone a little more advanced with some of our newer displays for the purpose of PC modding because so many people seem to use them.
As for communication, you may want to run your lines through an oscilloscope, just to see what's coming through. Also, a quick wiring note, Tx from your controller will go to Tx on your display. The labeling can be a little confusing so the lines could be reversed.
~Troy
Troy Clark
Design & Development
Matrix Orbital
Design & Development
Matrix Orbital
Hello Troy,
I'm sorry to inform you that the display is now working. All the fun is gone.
Like I sayd I contacted the PLC manufacturer and they told me to clear PLC send buffer just before sending any characters. This is because in industrial enviroment there could generate some error bytes from powerful servo cables etc and those bits could mess up the characters, because PLC is sending everything from the send buffer at once. OK, this didn't fix the problem, but can be useful when I finish this product and install it to a machine tool.
I also discussed about this PLC RS232 port with that same dude. He sayd it's RS level signal so it should not cause the problem. I also got the correct pin order. He also recommended Multiway software to be used to see exactly what does the PLC send. So I used it. First there was some partity error, eleven times "3F" and some zeros after that, parity error again, then my hex codes, some zeros and finally partity error again. No wonder the display didn't work. Ok, I cleared the whole memory area. Then I got 40 times "00". In PLC program TxD block there was 20 words to be send. I changed it to 1. Then it send "00". Ok, I put hex code 61 into D1000 and send it to Multiway and there it was and nothing else. So I took the cable and connected it to display, but it didn't work. Then we come to that what you sayd: Tx to Tx. I fixed the plug, connected it and it's working.
In PLC serial port, there pin 3 is Rx and pin 2 is Tx. In PC it's opposite way, so that's why PC and PLC worked together. Of course my connection to display was the same way. Although we tried it the correct way in some point, but then there was something wrong in the memory area. Anyway it's working now. This opens up many targets where I can use these kind of displays. I have to order more of these.
Thank you so much for helping us out.
I'm sorry to inform you that the display is now working. All the fun is gone.
Like I sayd I contacted the PLC manufacturer and they told me to clear PLC send buffer just before sending any characters. This is because in industrial enviroment there could generate some error bytes from powerful servo cables etc and those bits could mess up the characters, because PLC is sending everything from the send buffer at once. OK, this didn't fix the problem, but can be useful when I finish this product and install it to a machine tool.
I also discussed about this PLC RS232 port with that same dude. He sayd it's RS level signal so it should not cause the problem. I also got the correct pin order. He also recommended Multiway software to be used to see exactly what does the PLC send. So I used it. First there was some partity error, eleven times "3F" and some zeros after that, parity error again, then my hex codes, some zeros and finally partity error again. No wonder the display didn't work. Ok, I cleared the whole memory area. Then I got 40 times "00". In PLC program TxD block there was 20 words to be send. I changed it to 1. Then it send "00". Ok, I put hex code 61 into D1000 and send it to Multiway and there it was and nothing else. So I took the cable and connected it to display, but it didn't work. Then we come to that what you sayd: Tx to Tx. I fixed the plug, connected it and it's working.
In PLC serial port, there pin 3 is Rx and pin 2 is Tx. In PC it's opposite way, so that's why PC and PLC worked together. Of course my connection to display was the same way. Although we tried it the correct way in some point, but then there was something wrong in the memory area. Anyway it's working now. This opens up many targets where I can use these kind of displays. I have to order more of these.
Thank you so much for helping us out.
Kymppi
Hi Kymppi,
While I'm sad to see the troubleshooting complete, it's definitely great to hear that you've got that display up and running. Best of luck in your design process, and feel free to put up another post if you happen to run into any more trouble.
~Troy
While I'm sad to see the troubleshooting complete, it's definitely great to hear that you've got that display up and running. Best of luck in your design process, and feel free to put up another post if you happen to run into any more trouble.
~Troy
Troy Clark
Design & Development
Matrix Orbital
Design & Development
Matrix Orbital