Table 38 Using Transmitter In Constant-Current Source Mode - Honeywell ST 3000 User Manual

Background
ATTENTION
Procedure
Table 38 Using Transmitter in Constant-Current Source Mode
Step Press Key
1
2 DE READ
A
ID
3
NON-VOL
ENTER
(Yes)
4
INPUT
J
OUT-
PUT
5 SW VER
X
3
Z
0
126 ST 3000 Release 300 and SFC Model STS103 User's Manual
You can put the transmitter into a constant-current source mode to
checkout other instruments in the loop such as recorders, controllers,
and positioners. Using the SFC, you can tell the transmitter to change its
output to any value between 0 (4mA) and 100 (20mA) percent and
maintain that output. This makes it easy to verify loop operation through
the accurate simulation of transmitter output signals before bringing the
loop on line. Note that the constant-current source mode is also referred
to as the output mode.
The transmitter does not measure the input or update the output while it
is in the constant-current source mode.
The procedure in Table 38 outlines the steps for using a transmitter in its
output mode and clearing the output mode.
Read Display or Action
Connect SFC across loop wiring and
turn it on. If possible, locate SFC where
you can also view receiver instrument in
loop. If you want to verify loop
calibration, connect a precision
milliammeter or a voltmeter across a 250
ohm resistor in loop to compare
readings.
T A G N O .
T R I P S S E C U R E D ?
T A G N O .
S F C W O R K I N G . .
L I N D P T
P T
L I N D P P T
S F C W O R K I N G .
O U T P 1 P T
3 2 . 4
O U T P 1 P T
3 _
O U T P 1 P T
3 Ø _
See Figure 38 for sample SFC and
meter connections in a typical
analog loop with a differential
pressure type transmitter.
Be sure any switches that may trip
alarms or interlocks associated with
?
analog loop are secured or turned
off.
Confirm that "TRIPS" are secured
and establish communications with
.
sample transmitter PT 3011
A G N O .
3 Ø 1 1
Display shows current transmitter
3 0 1 1
output level and it will update every
. .
six seconds. Be sure to time your
next key press with an updated
3 0 1 1
display.
%
Key in 30% for desired output signal
3 0 1 1
level of 8.8 mA (2.2V).
%
3 0 1 1
%
Description
Continued on next page
6/05