GE DigitalFlow DF868 User Manual

Serial Communications 6-3
March 2008
The Optional RS485
Serial Interface
Although the standard RS232 serial interface included with the
Model DF868 is adequate for most applications, GE offers an
optional RS485 serial interface upgrade for special situations. The
Model DF868 is easily modified to provide RS485 communications,
and this section describes the wiring and use of the special RS232 to
RS485 converter.
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 DF868, 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 RS-485 output of the serial interface converter is wired to the
barrier strip.
Figure 6-1: Interface Converter Mounting
RS 232
TT
TR
T
SNR
XX
CD R
DN
CHAN 1
G
I
S
GNN
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

GE DigitalFlow DF868 Specifications

General

Brand	GE
Model	DigitalFlow DF868
Category	Measuring Instruments
Language	English