Teledyne 4250, Инструкция по установке и эксплуатации, Страница: 49 / 204

4250 Flow Meter
Section 2 Programming
2-21
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:
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:
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:
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.
OUTPUT RANGE
• 0 - 20 mA • • 4-20 mA •
SMOOTHING
• NONE • • 15 SEC • • 30 SEC • • 1 MIN •
MANUAL CONTROL (OUTPUT 0 = EXTERNAL)
OUTPUT 0 = 0.0 MA