GE 90-30 PLC Series Installation And Hardware Manual page 264

Expansion Port Pin Assignments
The following table lists the expansion port pin assignments you will need when building remote
cables. All connections between cables are point-to point, that is, pin 2 of one end to pin 2 of the
opposite end, pin 3 to pin 3, etc.
Table 10-2. Expansion Port Pin Assignments
I/O Expansion Bus Termination
When two or more baseplates are cabled together in an expansion system, the I/O expansion bus
must be properly terminated. The I/O bus must be terminated at the last baseplate in an expansion
system. Each signal pair is terminated with 120 ohm, 1/4 watt resistors wired between the
appropriate pins, as follows (see the above table, also):
The I/O bus termination can be done one of the following ways:
GFK-0356Q Chapter 10 Cables
Pin Number Signal Name
16 DIODT
17 DIODT/
24 DIOCLK
25 DIOCLK/
20 DRSEL
21 DRSEL/
12 DRPERR
13 DRPERR/
8 DRMRUN
9 DRMRUN/
2 DFRAME
3 DFRAME/
1 FGND
7 0V
pins
16 – 17; 24 – 25; 20 – 21; 12 – 13; 8 – 9; 2 – 3
By installing an I/O Bus Terminator Plug, catalog number IC693ACC307, on the last
expansion baseplate (local expansion baseplate or remote baseplate) in the system. The
Terminator Plug has a resistor pack physically mounted inside of a connector. The I/O Bus
Terminator Plug is shipped with each baseplate; only the last baseplate in the expansion chain
can have the I/O Bus Terminator Plug installed. Unused I/O Bus Terminator Plugs can be
discarded or saved as spares.
If an expansion system has only one expansion baseplate, the I/O bus can be terminated by
installing as the last cable, the 50 foot (15 meter) I/O Expansion cable, catalog number
IC693CBL302 or IC693CBL314. These cables have the termination resistors installed in the
end that connects to the expansion baseplate connector.
You can also build a custom cable with termination resistors wired to the appropriate pins for
installation at the end of the bus.
Function
I/O Serial Data Positive
I/O Serial Data Negative
I/O Serial Clock Positive
I/O Serial Clock Negative
Remote Select Positive
Remote Select Negative
Parity Error Positive
Parity Error Negative
Remote Run Positive
Remote Run Negative
Cycle Frame Positive
Cycle Frame Negative
Frame Ground for Cable Shield
Logic Ground
10
Cables
10-25