MR12 PLC module controller with AKP + 5 plug-in

Best.-Nr. 190.15519

The module controller MR12 is a microprocessor-controlled device for controlling district heating transfer stations with the option of modular expansion for a further seven mixer circuits and additional recording of the heat meter data and forwarding of all data to a higher-level network optimization computer in the boiler house consisting of:

– Three-point output for primary valve
– Two-point output for one heating circuit
– Two-point outlet for boiler 1
– Two-point output for boiler 2 (circulation circuit)

The first heating circuit can also be configured as a charging module circuit for the boiler.

Control features:
– Heating curve control dependent on outside temperature
– Return temperature-dependent return limitation
– three heating times for each day and heating circuit
– Heating times can also be configured as setback times
– Third period configurable as a blocking time
– Pump temperature cut-off depending on the room temperature
– Pump shutdown dependent on outside temperature
– Outside temperature averaging up to nine hours
– building coefficient (= building storage capacity)
– Boiler priority circuit / parallel boiler operation
– Boiler module load / boiler with changeover valve
– Boiler loading criteria:
a) two adjustable boiler loading periods
b) Falling below the minimum boiler setpoint
c) Manual preselection using the preselection switch
– Boiler shutdown criteria:
a) reaching the boiler setpoint
b) reaching the lower boiler sensor setpoint
c) End of boiler loading time
– Boiler load lock:
a) if the boiler charging temperature is too low
b) if the target boiler temperature is not reached

Optional: In addition, the MR12 can be equipped with an extension connection with the following signals:
* 3 pc pulse inputs for counting applications
* 1 pc additional PT1000 sensor input
* 1 pc additional analog input 0-10V

There are connection options for seven further heating circuit modules, an I / O module and a UART interface (COM-D) in the form of RS485 on the basic module controller.

With the heating circuit modules SCHNEID-heating circuit module-HK06 or SCHNEID-heating circuit module-HK12, the basic module controller can be expanded by seven additional mixer heating circuits.

Additional functions after expansion with appropriate modules:

– Optimization of the on / off times with a room sensor
– optional control via room sensor
– Control via adjustable room influence
– Room control via thermostat function
– Remote control for each heating circuit
– A maximum of four remote controls can be connected
– Eight external 0-10V (4-20mA) inputs e.g. for target values ​​via additional print

The outputs on the AKP board (terminal board) are designed on plug-in modules and are available in the following variants:
– MR12 plug-in module relay standard for MR12-AKP & HK12
– MR12 plug-in module relay R16 for MR12-AKP & HK12
– MR12 plug-in module PWM for MR12-AKP & HK12
PWM for controlling pumps with a PWM signal. In this case, the 230V terminal on the AKP is permanently connected to 230V. The PWM signal is connected to the plug-in module.
– MR12 plug-in module TRIAC for MR12-AKP & HK12
TRIAC module for controlling drives with a very high switching frequency (primary valves).
– MR12 plug-in module analog signal for MR12-AKP & HK12
0-10V for controlling pumps with 0-10V signal. In this case, the 230V terminal on the AKP is permanently connected to 230V. The 0-10V signal is connected to the plug-in module.
– MR12 plug-in module relay RPF for MR12-AKP & HK12
RPF for controlling pumps with start-stop input. In this case, the 230V terminal on the AKP is permanently connected to 230V. The potential-free relay contact is connected to the plug-in module.


The SCHNEID module controller MR12 is equipped with an analog operating level for easy operation of the most important functions. As an ad
serves a graphic display with 128×64 pixels.
A six-stage switch is available for setting the heating program. A setting potentiometer for normal operation or setback operation is available for fine adjustment of the room temperature.
The rest of the operation and setting of the control unit is carried out digitally via the display using a further six-step switch and three input buttons.

The MR12 offers the option of using internal wireless modules (WiFi, Bluetooth or radio). For communication with end devices such as Tablet, smartphones or to record future wireless sensors
(Outdoor, room sensor or radio FBR).
The interface cards are installed inside the controller (no ComBasis required).
This interface is shared with ComC on the COM basis.
The CPU can select between ComC external and internal.

There are connection options for seven further heating circuit modules, an I / O module and a UART interface (COM-D) in the form of RS485 on the basic module controller.
The UART is implemented on the backplane with a 4-pin plug 12V +/- RS485 D + / D- and for the direct connection of an FBR7 or SubCOM without the need for a CM08-COM base.


Connection options for a communication module are available on the module controller MR012.

With the communication board, the MR12 module controller can be equipped with up to three bus interfaces.

1. Standard bus for controller networking and system visualization via
2. Bus interface for consumption data acquisition (e.g. meter)
3. Internal controller bus for control networking (SubCOM)
A corresponding one can be used for each of the three bus interfaces depending on the application
Bus module.
– RS-232 module
Plug-in card module CM08-485
Plug-in card module CM08-422
Plug-in card module CM08-MBM-08 (MBus-Master 08)
Card module CM06-MBS (MBus slave)
-Socket card module USB
Plug-in card module CM08-TCP
Plug-in card module CM08-BT (Bluetooth)
Plug-in card module CM08-RF (radio)
Plug-in card module CM08-GPRS
Plug-in card module CM08-PGW BACNET
-Socket card module CM08-MP-Bus

4.COM-D: RS485 connection on the control panel for e.g. Remote control FBR12 / 14

Examples of networking:

COM-A: All data from the controller and the heat meter are transferred to the host computer in the boiler house via the special interface SCHNEID-FSS. (see WINMIOCS and FW-MANAGEMENT)
COM-B: Reading out the measurement data from heat meters, electricity meters and other external devices using the M-Bus interface (M-Bus protocol according to CEN TC176 WG4 and IEC1107).
Recorded data using the example of a heat meter: amount of heat, flow rate, flow temperature, return temperature, spread, power, flow rate, etc.
COM-C: Various SCHNEID control devices can be linked on the control side via an internal data bus. Corresponding setpoints as well as the centrally measured outside temperature are under the control devices
exchanged to enable optimized control.
COM-D: Intended for direct connection of an FBR12 / 14 or SubCOM without the need for a CM08 COM base.

Mechanical design:

The controller is delivered split. The control panel is provided with a plastic cover on the back, which can snap into a standard cutout. A flat cable connects the control unit to the rest of the control unit, which is installed in a plastic tray for top-hat rail mounting. The length of the connecting cable is approx. 50 cm.
The AKP board is equipped with 5 plug-in modules.

Scope of delivery & dimensions (HxWxD):
– PLC control panel: 96x144x57
– AKP with 5 plug-in modules (3 relays STD + 2 TRIAC): 100x145x36
– Connection cable 44-pin, 500mm standard length
– DIN rail (with 2 x covers and 2 x clips): 102x405x50

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