The Optional Rs485 Serial Interface; Interface Converter Mounting - GE Panametrics GF868 Programming Manual

April 2004
The Optional RS485
Serial Interface
Interface Converter
Mounting
LVD Shroud
Grounding Screw
6-4
Although the standard RS232 serial interface included with the
Model GF868 is adequate for most applications, GE Panametrics
offers an optional RS485 serial interface upgrade for special
situations. The Model GF868 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 GF868. 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.
A special bracket containing the serial interface converter and a three-
terminal barrier strip is mounted inside the Model GF868, just below
the RS232 terminal block (see Figure 6-1 below). The standard
terminal block is wired to the input of the serial interface
RS232
converter, and the RS485 output of the serial interface converter is
wired to the barrier strip.
RS 232
C D R T R
T T X X T
S R N
- XMT +
Barrier Strip
Red (XMT+)
Green (XMT-)
Figure 6-1: Interface Converter Mounting
D
C
CHAN 1
R
DN UP
S
S R R S
I T T I
G N N G
Mounting Bracket
Standoff
RS232 Terminal Block
Serial Communications