SIMOREG 6RA70 Siemens DC Master Variable Speed DC Drive
Design & Mode of Operation – Software Structure

Design and Mode of Operation6RA70 DC Master

Software structure

Two powerful microprocessors (C163 and C167) perform all closed-loop and drive control functions for the armature and field circuit. Closed-loop control functions are implemented in the software as program modules that are “wired up” via parameters.


All important quantities in the closed-loop control system can be accessed via connectors. They correspond to measuring points and can be accessed as digital values. 14 bits (16 384 steps) correspond to 100 % in the standard normalization. These values can be used for other purposes in the converters, e.g. to control a setpoint or change a limit. They can also be output via the operator panel, analog outputs and serial interfaces.

The following quantities are available via connectors:

  • Analog inputs and outputs
  • Inputs of actual-value sensing circuit
  • Inputs and outputs of rampfunction generator, limitations, gating unit, controllers, freely available software modules
  • Digital fixed setpoints
  • General quantities such as operating status, motor temperature, thyristor temperature, alarm memory, fault memory, hours run meter, processor capacity utilization


Binectors are digital control signals which can assume a value of “0” or “1”. They are employed, for example, to inject a setpoint or execute a control function. Binectors can also be output via the operator panel, binary outputs or serial interfaces.

The following states can be accessed via binectors:

  • Status of binary inputs
  • Fixed control bits
  • Status of controllers, limitations, faults, ramp-function generator, control words, status words

Intervention points

The inputs of software modules are defined at intervention points using the associated parameters. At the intervention point for connector signals, the connector number of the desired signal is entered in the relevant parameter so as to define which signal must act as the input quantity. It is therefore possible to use both analog inputs and signals from interfaces as well as internal variables to specify setpoints, additional setpoints, limitations, etc.

The number of the binector to act as the input quantity is entered atthe intervention point for binector signals. A control function can therefore be executed or a control bit output by means of either binary inputs, controls bits of the serial interfaces or control bits generated in the closed-loop control.

Switchover of parameter sets

4 copies of parameters with numbers ranging from P100 to P599 as well as some others are stored in the memory. Binectors can be used to select the active parameter set. This function allows, for example, up to four different motors to be operated alternately or four different gear changes to be implemented on one converter. The setting values for the following functions can be switched over:

  • Definition of motor and pulse encoder
  • Optimization of closed-loop control
  • Current and torque limitation
  • Conditioning of speed controller actual value
  • Speed controller
  • Closed-loop field current control
  • Closed-loop EMF control
  • Ramp-function generator
  • Speed limitation
  • Monitors and limit values
  • Digital setpoints
  • Technology controller
  • Motorized potentiometer
  • Friction compensation
  • Flywheel effect compensation
  • Speed controller adaptation

Switchover of BICO data sets

The BICa data set can be switched over by the control word (binector input). It is possible to select which connector or binector quantity must be applied at the intervention point. The control structure or control quantities can therefore be flexibly adapted.

Motorized potentiometer

The motorized potentiometer features control functions “Raise”, “Lower”, “Clockwise! Counterclockwise” and “Manual/Auto” and has its own rampfunction generator with mutually independent ramp time settings and a selectable rounding factor. The setting range (minimum and maximum output quantities) can be set by means of parameters. Control functions are specified via binectors.

In Automatic mode (“Auto” setting), the motorized potentiometer input is determined by a freely selectable quantity (connector number). It is possible to select whether the ramping times are effective or whether the input is switched directly through to the output.

In the “Manual” setting, the setpoint is adjusted with the “Raise setpoint” and “Lower setpoint” functions. It is also possible to define whether the output must be set to zero or the last value stored in the event of a power failure. The output quantity is freely available at a connector, e.g. for use as a main setpoint, additional setpoint or limitation.

Siemens Energy & Automation
SIMOREG DC Master Base Drive Operating Instructions