Cascade Loop Mode; Manual Mode; Setpoint Sources - Tescom ER3000 User Manual

the actual process pressure is obtained by installing a pressure transducer at the
output of the regulator or valve to provide the feedback signal to the ER3000.
External feedback can also be useful when using the ER3000 as a standalone
unit. It may be desirable to measure the pressure downstream from the
controller. For example, if the controller's output passes through a length of
pipe to a vessel and it is expected that there will be pressure drops in the pipe,
then it may be beneficial to install a pressure transducer at the vessel to provide
the feedback signal.

5.2.3 Cascade Loop Mode

Cascade loop mode implements one PID loop within another PID loop.
The inner loop uses the controller's internal sensor and the outer loop uses an
external sensor. This mode of operation creates more stability, but slows down
the response of the system.
(Note - For cascade control it is best to set the Integral Minimum = 0 and
Integral Maximum = 32767. This is because it is necessary to maintain a
positive pressure on the dome of the regulator to maintain output pressure from
the system.)

5.2.4 Manual Mode

In manual mode, no control algorithm is implemented. The setpoint is used to
directly control the unit's pulse width modulators. This mode can be useful for
system testing.
In Windows ER3000 Signal Generator Screen or DOS Tune a setpoint value of:
In Windows ER3000 Read/Write Screen or DOS ERTALK a setpoint value of:

5.3 Setpoint sources

The setpoint for the unit can be derived from one of three sources. It can be:
• Transmitted over the RS485 interface.
• Input from an analog signal (4-20mA, 1-5V, or 0-10V).
• Supplied by an embedded profile.
30 ER3000 User Manual
0% = Fully opens the exhaust solenoid valve
50% = Closes both solenoid valves.
100% = Fully opens the inlet solenoid valve
0x0706 = Fully opens the exhaust solenoid valve
0x0800 = Closes both solenoid valves.
0x08fa = Fully opens the inlet solenoid valve