Process Variable Bipolar; 20% Offset Of Process Variable; Square Root Of Process Variable; Loop Output Address - Siemens SIMATIC 505 User Manual

You must specify the engineering values that correspond to the upper
range of the input span.

Process Variable Bipolar

Select YES or NO to specify analog inputs as bipolar or not. Bipolar
inputs span have spans of -5 to 5 volts, or -10 to 10 volts.

20% Offset of Process Variable

Select No for no offset, and Yes for 20% offset. A span of 0 to 5.0 volts
(0 to 20 milliamps ) is referred to as a span of 0 to 100%. A span of 1 to
5.0 volts (4 to 20 milliamps) is referred to as a span of 20% to 100%
(20% offset on the process variable).

Square Root of Process Variable

Select Yes if the input for the process variable is from a device (such as
an orifice meter) that requires a square root calculation to determine the
correct value to use.

Loop Output Address

Enter an address: V, or WY, in the Loop Output Address field. Select
NONE when you do not want the loop to write the output to an address.
Use the LOOP OUTPUT ADDRESS field to specify the address into
which the loop writes the value of the output. You can select NONE in
situations such as cascaded loops in which the outer loop does not require
an output address.

Output is Bipolar

Select YES or NO in the OUTPUT IS BIPOLAR field. If you Select Yes,
the output range is -32000 to +32000.

20% Offset on Output

Select YES or NO in the 20% OFFSET ON OUTPUT field.
If you Select No for both fields (no 20% Offset and output is not bipolar),
then the output range is 0 to +32000.

Ramp/Soak for SP

Select YES or NO in the RAMP/SOAK FOR SP field to indicate whether
a ramp/soak program for the loop is to be executed.

Alarm Deadband

Enter a value in engineering units for the Alarm deadband in the ALARM
DEADBAND field. When you specify an Alarm deadband, the controller
can provide hysteriesis on all Alarms except the rate of change Alarm to
prevent them from chattering when the process variable is near one of the
Alarm limits. The loop does not exit the alarm condition until the process
variable has come inside the alarm limit minus the deadband.

Monitor Low-Low/High-High

Select Yes to have the controller monitor the Low-Low/High-High Loop;
otherwise, select No. The Low-Low/High-High can be entered as values
requiring critical action.
154 • • • • 9 - PID Loops
Simatic 505 SoftShop