Hi,
Our customer plant has about 20 nodes of PLC running in DH+. Everything has be running fine for couple of years. Recently when they purchase the RSLogix 5 and go online with the PLC thru 1784-PCMK from the network programming port, some of the PLC will shutdown itself. The PLC that shutdown may varies. Previously customer is using the DOS programming software and everything is fine.
We went to the site and check their connection/wiring, we found out that the daisy chain DH+ network is fine, but there is a point where the programming port is tap direct for a node (terminal block)). This is where the particular node has 3 wires, 2 for the DH+ daisy chain and another cable for programming port (to hook up our notebook).
I'm not sure if this is correct or wrong.
Question:
1) We ask our customer to daisy chain the programming port at the end of the node, but the terminator resistor should be located at the last PLC or at the porgramming port (9-pin)?
2) The customer do argue that tapping a programming port from one point/node is the same concept as the 8-pin Mini DIN port on the PLC-5 CPU where they are shared. For example Channel 1A of a PLC-5/40 has a 8-pin Mini DIN (programming) & a 3 pin DH+ (networking). Can anyone please clarify me how's the 8-pin Mini DIN (DH+) port of the CPU work?
Thanks in advance
Our customer plant has about 20 nodes of PLC running in DH+. Everything has be running fine for couple of years. Recently when they purchase the RSLogix 5 and go online with the PLC thru 1784-PCMK from the network programming port, some of the PLC will shutdown itself. The PLC that shutdown may varies. Previously customer is using the DOS programming software and everything is fine.
We went to the site and check their connection/wiring, we found out that the daisy chain DH+ network is fine, but there is a point where the programming port is tap direct for a node (terminal block)). This is where the particular node has 3 wires, 2 for the DH+ daisy chain and another cable for programming port (to hook up our notebook).
I'm not sure if this is correct or wrong.
Question:
1) We ask our customer to daisy chain the programming port at the end of the node, but the terminator resistor should be located at the last PLC or at the porgramming port (9-pin)?
2) The customer do argue that tapping a programming port from one point/node is the same concept as the 8-pin Mini DIN port on the PLC-5 CPU where they are shared. For example Channel 1A of a PLC-5/40 has a 8-pin Mini DIN (programming) & a 3 pin DH+ (networking). Can anyone please clarify me how's the 8-pin Mini DIN (DH+) port of the CPU work?
Thanks in advance