PRESSURE CONTROLLER operating manual
35
Commanding a New Setpoint
Before attempting to send setpoints to your pressure controller serially,
confirm that its setpoint source is set to
Serial/Front Panel
by selecting
MENU
→
CONTROL
→
ADV CONTROL
→
SETPT SOURCE
.
There are two ways to command a new setpoint over a serial connection,
as described below. In either of these methods, the data frame returns
the new setpoint value when it has been accepted as a valid setpoint.
Sending Setpoints as Floating Point Numbers
This is how to send the desired setpoint value as a floating point number
in the selected engineering units:
New setpoint:
[unit ID]
s
[floating point number setpoint]
Example:
as5.44
(setpoint of +5.44 PSIG)
New setpoint:
[unit ID]
s
[floating point number setpoint]
Example:
as-15.00
(setpoint of −15.00 PSIG)
Sending Setpoints as Integers
In this method, your controller’s
full scale range (FS)
is represented by
a value of 64000, and a zero setpoint is represented by 0. To calculate
your intended setpoint, use the following formula:
Integer value =
64000 ×
[desired setpoint]
/
[device full scale]
Example:
A desired setpoint of +6.00 PSIG on a 15 PSIG pressure controller
is calculated as 64000 × 6.00 / 15.00 =
25600
. The command to assign
the setpoint based on this integer value is:
New setpoint:
[unit ID][setpoint as integer
where 64000 is FS]
Example:
a25600
(setpoint of +6.00 PSIG)
