Device Net Communications Failure
Device Net Communications Failure
(OP)
Hi all. We have an HVAC MCC supplied by one of our vendors. In their systems, they have provided Device Net Devices for communication and provided 24Vdc power supplies within the 600V MCCs. The power supply is supplied by a 600V-120V step down transformer feeding two units of 120VAC-24Vdc power supplies. These power supplies feeds the Device Nets.
There is a Buffer that is connected in parallel to the 24Vdc Power Supply output terminals. The device nets are powered and there is 24Vdc voltage on their power inputs. The problem is that, the device nets are communicating with DCS. Howeverm, if they bypass the buffer (disconnected) and wire the device nets directly to the 24Vdc power supplies, the communication is working.
The buffer spec is in this link:
http:/ /literatur e.rockwell automation .com/idc/g roups/lite rature/doc uments/ap/ 1606-ap029 _-en-e.pdf
Is this because of the buffer emitting EMIs or noise of some sort that it disrupts the device net comms? or there is something we are missing here?
There is a Buffer that is connected in parallel to the 24Vdc Power Supply output terminals. The device nets are powered and there is 24Vdc voltage on their power inputs. The problem is that, the device nets are communicating with DCS. Howeverm, if they bypass the buffer (disconnected) and wire the device nets directly to the 24Vdc power supplies, the communication is working.
The buffer spec is in this link:
http:/
Is this because of the buffer emitting EMIs or noise of some sort that it disrupts the device net comms? or there is something we are missing here?






RE: Device Net Communications Failure
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RE: Device Net Communications Failure
RE: Device Net Communications Failure
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RE: Device Net Communications Failure