Hach sc1000 - Manual (Page 105)

103
Advanced Operations
With the PWM CONTROL/PID CONTROL the relay generates a PWM
(Pulse-Width-Modulated) signal with an on/off ratio trying to control the process value.
6.3.3.8 Function set to FREQ. Control / Linear working mode
INPUT VALUE
Displays the process value read from the selected source after it has been processed by the
internal formula parser (if prompted).
PWM CONTROL/PID CONTROL
FREQ. Control / Linear
SET FUNCTION
Default value: LINEAR
There are two SET FUNCTION menus.
First menu: Selects the basic function of the relay.
Second menu: Defines whether the output frequency signal is depending linear to the process
value or the output frequency signal is working as a PID controller.
LINEAR Signal is linearly dependent on the process value.
PID CONTROL Signal works as a PID controller.
SET TRANSFER
Default value: 0 seconds
Sets a substitute output frequency when some error conditions are detected in the selected
source or if the source is missing.
HIGH ALARM
Default value: 1 second
Sets the duration cycle in seconds of the output frequency when the process value reaches the
HIGH ALARM limit.
LOW ALARM
Default value: 10 seconds
Sets the duration cycle in seconds of the output frequency when the process value reaches the
LOW ALARM limit.
HIGH ALARM
Default value: 15
Determines at which process value the duration cycle of the output frequency has got the value
set at HIGH ALARM.
LOW ALARM
Default value: 5
Determines at which process value the duration cycle of the output frequency has got the value
set at LOW ALARM.
INPUT VALUE
Displays the process value read from the selected source after it has been processed by the
internal formula parser (if prompted).