Micromod MOD: 30ML Operation and Template Setup - Manual (Page 61)

MOD 30ML Multiloop Controller
OPERATION
3-29
3.15 STARTUP
Procedures may vary from application to application, depending upon individual requirements
and control loop setup. The initial operating mode (usually manual), the set-point source
(usually local), set-point value, and control output can be configured for specified safe values
when power is first applied to the instrument. Each time a control application is first started
up, check all these items before turn-on.
3.15.1 Startup Without Set-Point Tracking
To start up a control loop in the manual mode:
1. Select the required loop using the TAG key.
2. Place the loop in manual mode with local set-point.
3. Adjust local set-point to starting value required for process variable.
4. Adjust manual output to a safe starting value for the process. This is usually below 0% or
above 100% of span.
5. Open block valve ahead of control valve or perform any other procedure required to
make the process variable available, such as starting a pump, turning on a power supply,
etc.
6. Manually adjust control output to bring process variable to set-point value. Ramping the
output should be slow enough to allow the process to respond to the change without
overshooting the set-point. Process is now operating under manual control with process
at the set-point.
3.15.2 Startup With Set-Point Tracking
The startup procedure is simplified when set-point tracking is used. With the control loop in
the manual mode, the set-point tracks the process so that the process and set-point values
are together when the operator switches to the automatic mode.
To start up the controller with set-point tracking:
1. Select the required loop using the TAG key.
2. Place the loop in manual mode.
3. Adjust manual output to a safe starting value for the process. This is usually below 0% or
above 100% of span.
4. Open block valve ahead of control valve or perform any other procedure required to
make the process variable available, such as starting a pump, turning on a power supply,
etc.