dh+ plc5 to new clx 1756 dhrio

Can i terminate(put resistor in terminal of channel a)the blue hose of an existing plc5 dh+ network to a new 1756-dhrio in new clx rack without changing the plc5 code or do i have to define it in io of plc5? So from node 1-27, node1 being the plc5 scanner, the new will be 1-20+node 30,node of dhrio, both in 115k baud rate.

You do not have to reconfigure any of the PLC-5 controllers in order to connect a 1756-DHRIO module to the DH+ network.

The most important rules of DH+ are:

• Each device must have a unique Station Address.
  
• All devices must be configured for the same data rate (57.6, 115.2, 230.4) kb/s.
  
• Two (2) termination resistors must be installed, at the physical ends of the network.
  
• The termination resistors must be 150 ohm for 57.6 or 115.2 kb/s operation, or 82 ohm for 230.4 kb/s operation.

I did the config but i used 2 dhrio cards to isolate the node 1-17 and on dhrio 1 and 20-27 in dhrio 2 so both dhrio have resistors but im getting dupl in display. Is that not possible?also tried removing 1st dhrio, still gives dupl scanner in display.must be network problem.

I don't understand your network architecture, so I can't give you advice on what sort of connection is appropriate for your system.

In general the "DUPL NODE" message means that your DHRIO module has a DH+ node number that is the same as an existing node on the network.

Turns out the plc5 with channel 2b configured as RIO scanner was in the same network as the new dhrio configured as RIO scanner hence dupl. Since i stiill needed to connect the clx to dhrio, i connected the 1st dhrio to the channel 2a of plc5 configured as dh+ then do messaging. My reason here is you cant message between plc5 and clx via rio(since it will have dupl).

to verify, i can daisy chain the new dhrio card to the existing Remote IO network in between any node, not just in beginning or at the end right?

Please explain what you are trying to do.

Your post didn't mention Remote I/O (RIO) protocol until today, other than using the term "scanner".

RIO and DH+ use the same wiring, and the ports can be configured for either protocol on most PLC-5 controllers.

But they are not the same ! You cannot connect RIO devices to a DH+ network, and vice-versa.

Yes, you can connect a 1756-DHRIO at any physical location on the daisy-chain network.

But you still need to configure the devices correctly.

Start by explaining what you are trying to do.

Are you modifying a RIO network, or modifying a DH+ network >

sorry for the confusion. i didnt have the whole network figured until yesterday. the 2 networks are a) dh+ which is where I connect to the PLC5 b) and RIO network with 7 racks.
the solution was to disconnect the channel 2b of PLC5 then connect the channel B of 1756 dhrio in between 2 RIO nodes. then connect channel A of dhrio to the dh+ trunk network using SC station to talk to channel 2A of PLC5.

I definitely didn't read it as being both a DH+ network and a RIO network.

Thank you for explaining, and I'm glad you got your networking working correctly !