Function control
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Function control
In the solar and heating section, a number of functions perform important tasks that could lead to
wrong reactions if there's a malfunction. For instance, if a defective cylinder sensor in the solar sys-
tem detects temperatures that are too low, the solar system will run under false premises and take
heat out of the cylinder. The module FUNCTION CONTROL can be used to monitor various operating
modes and will issue an error message if there's a malfunction or block the inoperable function via its
enable.
Input
variables:
Output
variables:
Control value a
Status error value, indication of the output
Control value b
Status error difference, indication of the output
Enable differential control
Simple description of the function:
This function allows for two sensors (control value a, b) to be monitored in order to detect a short-
circuit, an interruption and the maximum admissible temperature difference. Likewise, it is possible to
monitor a sensor or temperature via a defined threshold value.
Special features:
If there is interruption or short-circuit that affects the basic function of the module, an error
message is issued only after 30 seconds.
In addition, a temperature threshold or difference can be monitored using “ENABLE DIFF
CTRL” If this control has been enabled, then the following applies:
If sensors are assigned to both control values, the monitoring of the differences is active.
If control value b is set to
User
, it is an adjustable temperature threshold that applies for the
control value a as a limit value to be monitored.
If the monitoring of the difference is not enabled, the message DIFFEREN. OK appears in the
error display nevertheless. It generally suffices to monitor the circulation of just one circuit in
solar warm water systems with multiple consumers (via enable). If another circuit is running,
the message of monitoring should still be displayed.
If only one sensor is monitored (control value b =
User
) or if the difference is monitored, a mal-
function is only messaged after an error time that can be set. This helps to prevent unjustified
error messages caused by temperature peaks when the system is starting.
The parameters are found in their own parameter menu to provide an overview of the error
evaluation at all times.
Via the command “Save error: yes", the display
ERROR
remains until it is manually deleted
even after the error has disappeared.
Warning:
Sometimes it makes sense to link one of the output variables directly to the control output to create
a 0 to 10 V or PWM signal. Linking this function is only allowed using control output A15, not with
output A16.
