Hello,

_Abhi_

I want to ask you when and under which circumstances we choose to use DP-DP coupler and OLM

I try explain generally. As names of devices explain all, DP DP Coupler is some bridge between 2 DP networks but this means that you can exchange data between 2 independed DP networks. All is configured as some I/O data area on DP-DP coupler and also each side Master then can set data to other side of Coupler as area is configured. DP DP coupler acts simply as DP Slave to each DP network Master. One important rule is that data structure need to be same for both sides, so next important is that on one side are data as Inputs and on other side are Outputs. With OLM also name explains all, it is simple Optical line converter to physical RS485 as PB or MPI is. Very easy.