Serial Communications
6-5
March 2008
Optional RS485 Serial
Interface
Although the standard RS232 serial interface included with the
Model GS868 is adequate for most applications, GE offers an
optional RS485 serial interface upgrade for special situations. The
Model GS868 is easily modified to provide RS485 communications,
and this section describes the wiring and use of the special RS232 to
RS485 converter.
IMPORTANT:
This section refers to the PC communications port
(labelled “RS232” on the main board). If you have a
MODBUS card installed, the terminal block on that
card will always be RS485. The MODBUS card only
sends MODBUS data and cannot be used to set up
the GS868. IDM communication always passes via
the RS232 port described here.
Note:
For compliance with the European Union’s Low Voltage
Directive (73/23/EEC), this unit requires an external power
disconnect device such as a switch or circuit breaker. The
disconnect device must be marked as such, clearly visible,
directly accessible, and located within 1.8 m (6 ft) of the
electronics console.
Interface Converter
Mounting
A special bracket containing the serial interface converter and a three-
terminal barrier strip is mounted inside the Model GS868, just below
the RS232 terminal block (see Figure 6-1 below). The standard
RS232
terminal block is wired to the input of the serial interface converter,
and the RS485 output of the serial interface converter is wired to the
barrier strip.
Figure 6-1: Interface Converter Mounting
RS 232
T T
T
R
T
S
N
R
X
X
C D
R
DN
CHAN 1
G
I
S
G
N N
S
I
R
T
R
T
UP
D
C
R
S
- XMT +
Red (XMT+)
RS232 Terminal Block
Standoff
Mounting Bracket
Barrier Strip
LVD Shroud
Green (XMT–)
Grounding
Screw
G N/L2 L1 AC
G – + DC
Summary of Contents for DigitalFlow GS868
Page 7: ...Chapter 1 ...
Page 59: ...Chapter 2 ...
Page 77: ...Chapter 3 ...
Page 90: ...Chapter 4 ...
Page 104: ...Chapter 5 ...
Page 110: ...Chapter 6 ...
Page 122: ...Appendix A ...
Page 131: ...Appendix B ...
Page 132: ...Data Records Option Cards Installed B 1 Initial Setup Data B 2 ...
Page 136: ...Appendix C ...
Page 156: ...Appendix D ...