lxman
Member
Howdy All,
I am currently in the UK and am trying to replace an old PC based HMI. The original PC had a 1784-KTX which communicated to a PLC5/40V Rev. B Series E Enhanced over DH+ at 115200 on channel 1B. Communications were ok with the old setup, but the HMI had some issues which I needed to correct. The old PC was running NT 4.0, so I grabbed the source for the HMI and set about to replace the PC.
I purchased a 1784-PKTX, bought a cheap desktop unit and set it up with Win2K and set to work. The program modifications went well, the card plugged in and Windows recognized it, installed the driver, etc.
Then I came to the customer's site. On trying to connect to the existing "blue hose," I am having issues.
On the 1784-PKTX 3-pin phoenix connector I hook up pin 1 as clear, pin 2 as shield and pin 3 as blue. On the PLC5 end, I hook up with the same connection. Here's the rub. Whenever I plug into the PLC5, the green LED stops flashing (just stays off). As soon as I unplug the phoenix, it starts flashing again. I have tried swapping blue and clear, running blue to pin 1 on one end and to pin 3 on the other end, using 82 ohm resistors on both ends, using 150 ohm resistors on both ends, mixing, matching, swapping, etc. I cannot get this to work with the existing cable.
OK, not one to be defeated, I took the PC over close to the PLC and made up a short cable. BINGO! Now I can communicate with the controller. So, I presume that the issue is the cable and inform the customer that he will need to replace the cable in order to get his new HMI working. I depart into happy land and begin planning my return to the other side of the pond.
Well, this AM, I get a call from the customer. Now he informs me that the short cable will not even work, and he is seeing the same symptom. When the cable is plugged into the PLC5, the green blinking light stops blinking and goes dark until the (short) cable is unplugged.
Alright, I call AB tech support locally, and the technician I talked to sends me a tech bulletin excerpt and tells me that I need to hook up the following:
1784-PKTX end
1 Clear wire
2 Shield
3 Blue wire
PLC5 end
1 Clear wire
2 Blue wire
3 No connection
OK, I'll try this, but it seems a little confusing to me. I thought a DH+ connection to a 3-pin phoenix was the same wherever you were on the network.
Well, any further ideas from anyone on what could be going on?
Thanks much for your help.
I am currently in the UK and am trying to replace an old PC based HMI. The original PC had a 1784-KTX which communicated to a PLC5/40V Rev. B Series E Enhanced over DH+ at 115200 on channel 1B. Communications were ok with the old setup, but the HMI had some issues which I needed to correct. The old PC was running NT 4.0, so I grabbed the source for the HMI and set about to replace the PC.
I purchased a 1784-PKTX, bought a cheap desktop unit and set it up with Win2K and set to work. The program modifications went well, the card plugged in and Windows recognized it, installed the driver, etc.
Then I came to the customer's site. On trying to connect to the existing "blue hose," I am having issues.
On the 1784-PKTX 3-pin phoenix connector I hook up pin 1 as clear, pin 2 as shield and pin 3 as blue. On the PLC5 end, I hook up with the same connection. Here's the rub. Whenever I plug into the PLC5, the green LED stops flashing (just stays off). As soon as I unplug the phoenix, it starts flashing again. I have tried swapping blue and clear, running blue to pin 1 on one end and to pin 3 on the other end, using 82 ohm resistors on both ends, using 150 ohm resistors on both ends, mixing, matching, swapping, etc. I cannot get this to work with the existing cable.
OK, not one to be defeated, I took the PC over close to the PLC and made up a short cable. BINGO! Now I can communicate with the controller. So, I presume that the issue is the cable and inform the customer that he will need to replace the cable in order to get his new HMI working. I depart into happy land and begin planning my return to the other side of the pond.
Well, this AM, I get a call from the customer. Now he informs me that the short cable will not even work, and he is seeing the same symptom. When the cable is plugged into the PLC5, the green blinking light stops blinking and goes dark until the (short) cable is unplugged.
Alright, I call AB tech support locally, and the technician I talked to sends me a tech bulletin excerpt and tells me that I need to hook up the following:
1784-PKTX end
1 Clear wire
2 Shield
3 Blue wire
PLC5 end
1 Clear wire
2 Blue wire
3 No connection
OK, I'll try this, but it seems a little confusing to me. I thought a DH+ connection to a 3-pin phoenix was the same wherever you were on the network.
Well, any further ideas from anyone on what could be going on?
Thanks much for your help.