Instruction manual

54 RFT9739 Rack-Mount Transmitter Instruction Manual
Output Wiring
continued
5.8 Remote-zero switch
The transmitter can be zeroed from a remote switch. If the transmitter
display indicates flow rate, this contact will zero the flowmeter. If the
transmitter display indicates flow total, this contact will reset the flow
total.
•
Section 6.4
, page 65, describes the flowmeter zeroing procedure.
•
Section 6.5
, page 67, describes the totalizer reset procedure.
The switch must be a momentary-type contact, normally open, close to
zero, and must carry 1 mA of current in the closed position. The open
circuit voltage is 5 VDC.
Use terminals CN2-D20 and CN2-D26 for the remote switch. Terminal
D26 serves as a common return for the external-switch input,
frequency/pulse output, dual-channel frequency output, and control
output. See
Figure 5-28
.
Figure 5-28.
Wiring to remote-zero
switch
Remote
switch
RFT9739
output terminals
ZERO+ (signal line)
RETURN (ground)