SNAP PID MODULE REFERENCE
SNAP PID Module User’s Guide
19
4
PID Inverse
Sets PID output to use an inverted or non-inverted signal.
0 = PID output is not inverted.
1 = PID output is inverted. Inversion occurs only after the PID
calculation has occurred. For the PID module, output limits and
outputs made in Manual mode are absolute values and are not
inverted.
0
(not
inverted)
Manual
5
(not used)
n/a
n/a
6
(not used)
n/a
n/a
7
PID Mode
Sets SNAP-PID-V module’s calculation mode (Auto/On or
Manual/Off).
0 = Manual mode (Off). The PID scan timer is stopped and reset.
Any current PID calculations are cancelled, and all PID variables
are reinitialized. PID output value is sent to either current or voltage
outputs. Changes to all PID variables and control bits are allowed,
as well as direct writes to PID output.
Note:
If the Process Quality status flag bit is set, Auto mode cannot
be used until the flag is cleared.
1= Auto mode (On). The PID scan timer is active, and PID values
are calculated and executed. PID output value is sent
simultaneously to both current and voltage outputs as a percent of
the output scale. Changes to scantime variables are ignored, and
will result in an error. Changes to control bits are allowed except
where noted. Direct writes to PID output is not allowed.
Note:
If the Process Quality status flag bit is set, PID output stops
and PID mode is forced to Manual.
0
(Manual/
Off)
n/a
0*
Setpoint Source
Sets an internal or external source for the setpoint value.
0 = Setpoint obtained from external analog source connected to
SNAP-PID-V channel 0.
1 = Setpoint obtained from internal value.
0
(external
source)
Manual or Auto
1*
(not used)
n/a
n/a
2*
(not used)
n/a
n/a
3*
(not used)
n/a
n/a
4*
(not used)
n/a
n/a
5*
(not used)
n/a
n/a
6*
(not used)
n/a
n/a
7*
(not used)
n/a
n/a
* Second 8-bit byte in control word
Bit
Bit Name and Description
Default
To Modify,
Use Mode...
