User`s guide

Page 102

Controlinc 1746-C (Version 5.21) Network Master Users Guide (2004-11-18)

6.3. App Note: For Diagnostics - Know the Physical Network

Wiring

When diagnosing a troublesome network, it can become impossible to solve some problems without

knowing the physical layout of the network (also called “as built” by contractors). If not known, it is

possible that the physical layout will have to be “traced out”.

For instance, if you are having “COM1 or COM2

” problems in which you are having problems

communicating in one direction and not the other (table [1] values are 1 or 2) then if you know the

physical wiring of the network, it will make sense as to which ones are having problems and why.

Without knowing the physical layout of the network, the information in this table can be meaningless.

Another scenario … if an E>Net ring, if the contractor accidentally swapped the Port A & B wires at one

actuator, normal communications will still work fine. However, “COM1 or COM2

” errors in table [1] will

give incorrect indications as to where the problem lies.