6 special i/o functions, 3 clearing the analog input configuration, 1 on/off and pid control – Infinite Peripherals SCOM-100 User Manual
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SCOM-100, User guide
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4.5.3 Clearing the analog input configuration
Any analog input configuration settings such as alarm, naming, messaging and scaling can be cleared
using the command:
1210,m,n
1210: Command
ID
m:
Module number (0 for SCOM-100 main unit, 1-4 for AI-4 expansion
units)
n:
Input number (1-2 for SCOM-100 main unit, 1-4 for AI-4 expansion units)
4.5.4 Setting the analog inputs alarm deadband
A special command is available to configure alarm deadband (hysteresis) for all
analog inputs. Alarm deadband is a small range in the total scale of the input signal
where alarm states remain indifferent, holding on their last value - in order to avoid
frequent SMS transmissions.
The Alarm deadband is given as a percent of the total scale.
1290,d
1290: Command
ID
d:
Alarm deadband value in % up to 5% of the total scale (0-5% in 0.1
steps). Example: d =2.3%
4.6 Special I/O Functions
4.6.1 ON/OFF and PID control
Up to four ON/OFF or PID control function blocks are available. Each block uses an analog input
for measuring the process value and a digital output for control.
Function block configuration
1250,id,m,n,m1,n1,sp,g,it,dt,ct,h
1250: Command
ID.
id:
Function block ID (1-4).
m:
Module number (0 for SCOM-100 main unit, 1-4 for AI-4 expansion
units).
n:
Input number (1-2 for SCOM-100 main unit, 1-4 for AI-4 expansion
units).
m1:
Module number (0 for SCOM-100 main unit, 1-8 for DI-42 I/O expansion
units).
n1:
Output number (1-4 for SCOM-100 main unit, 1-2 for DI-42 I/O
expansion units).
sp:
Set point value in the range of the analog input scale.
g:
‘Gain’ value (P) between 1 and 100%. The block function depends on
the ‘Gain’ value: A zero value selects the ON/OFF control function. A
non zero value selects the PID function.
it:
‘Integral time’ (I) value between 1-1000 sec. A zero value disables the
integral part (not relevant for ON/OFF control).
dt:
‘Derivative time’ (D) value between 1-200 sec. A zero value disables the
drivative part (not relevant for ON/OFF control)..
ct:
‘Cycle time’ value between 1 and 15 minutes, representing the pulse
width modulation period of the digital output (not relevant for ON/OFF
control).