77
promesstec GmbH
I Niedersachsenstraße 4 I D- 48465 Schüttorf I Tel.:+49 (0)5923/ 90 229 0 I Fax:+49 (0)5923/ 90 229 29
E-Mail: [email protected] I Internet: www.promesstec.com
7.6 Difference regulations
In some applications it is necessary to control the deviation of
two process signals. To set this differential control, please use
the following parameters:
FUNC = FULL
IN1. IN1L, IN1H are set according to input 1.
IN2. IN2L, IN2H are set according to input 2.
IN1U, DP1, IN2U, DP2 are set according to input 1 & 2.
PVMD = P1-2 or P2-1
SPMD = SP1.2
The control of PV2 will run parallel to PV1, see picture:
Difference regulation
The process display shows the difference PV1 - PV2 if PVMD = P1-2 or the
difference PV2
– PV1 if PVMD = P2-1. If you want to display one of the process
values PV1 or PV2, you can change the settings as described in chapter 6.22.
Error messages:
If PVMD = P1-2 or P2-1 and at the same time SPMD = PV1
or PV2, an error
is displayed. In this case the
settings for IN1U and IN2U as well as DP1 and DP2 must
be the same, otherwise error
is displayed.
7.7 Control limitation
In some applications, the heating or cooling may be oversized. In order to prevent a
strong over- or underrun of the setpoint, the control limitation can be activated.
The control limit for output 1 is PL1, can be found in the user menu. If output 2 is not
used,
(OUT2 ≠ COOL), the associated parameter PL2 is hidden. If the controller is in
ON-OFF control mode, PL1 and PL2 are hidden.
Setting the control limit
Press
for 3 sec., then repeatedly until PL1 or PL2 appears in the display. PL1 and
PL2 can be set between 0 and 100% via the up and down keys.
Error messages
Settings
PVMD = P1-2
or
PVMD = P2-1
SPMD = SP1.2
