Teledyne 4250 Installation And Operation Manual page 49

MANUAL CONTROL will appear if you continue moving to the
right. "RANGE" will appear with the ANALOG OUTPUT menu
if the optional internal 4-20 mA converter is present in the flow
meter. If you select RANGE, the following will appear:
OUTPUT RANGE
• 0 - 20 mA • • 4-20 mA •
This menu lets you select the current value for zero percent
(baseline) compatible with your equipment (internal 4-20 mA
board only).
If you select SMOOTHING from the ANALOG OUTPUT menu
the following will appear:
SMOOTHING
• NONE • • 15 SEC • • 30 SEC • • 1 MIN •
The SMOOTHING option lets you stabilize operation of the
outputs by preventing a rapid reaction to sudden sharp changes
in the condition being monitored that quickly return to normal
(transients). Selection of a smoothing interval will prevent the
equipment controlled by the 4-20 mA loop from reacting too
quickly, too much, or operating erratically. A low-pass filter algo-
rithm is incorporated in the software.
If you select the MANUAL CONTROL option from the ANALOG
OUTPUT menu the following will appear:
MANUAL CONTROL (OUTPUT 0 = EXTERNAL)
OUTPUT 0 = 0.0 MA
This option lets you control the operation of a 4-20 mA loop to
check the operation of equipment controlled by the loop at any
level from 0 to 100%. After connecting a 4-20 mA output to a con-
trolled device, you can program the flow meter to put a specified
current on a specific analog output. If you are using the external
4-20 mA converter, the Analog Output number will be zero.
Note
Selecting the MANUAL CONTROL option and programming
any one of the ports will prevent the values transmitted by the
other active 4-20 mA ports from being updated until the test is
completed. The other ports will continue to transmit whatever
value they held at the start of the test. Exiting from the MAN-
UAL CONTROL menu at the end of the test will return all active
4-20 mA ports to normal operation.
Programming for the conditions and values that determine the
operation of the 4-20 mA loop (or loops) is done in Programming
Step 2, following the entry of FLOW RATE AT MAXIMUM
HEAD.
4250 Flow Meter
Section 2 Programming
2-21