Dual-track construction of digital systems GTD
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Dual-track construction of digital systems GTD

Dual-track construction of digital systems GTD

 

 

To control the functional software is carried out analysis of the implementation of all program modules in full. The successful implementation of each module of the program fixed by a special counter, and as a checksum to determine whether the implementation of all management and control routines.

To protect against cycling program at the end of each cycle generates an interrupt timer program. To control information are renewed at the beginning of the cycle all the information coming from the previous cycle, it receives a sign of "old." The information in the current cycle gets a sign of a "new". The information before the issuance of the actuators or other channels is checked for signs of the "new". This and a number of other methods allow to organize effective monitoring of the channel system.

With two-channel construction of digital control systems, there is an additional opportunity to use to monitor the identical information available in each channel. Identical information for inter-channel cross-matching is transmitted between channels in the form of checksums. The coincidence of the corresponding checksums in both channels allows the control signals to be outputted to the respective actuators. If this does not happen, then each channel returns to the beginning of the cycle and repeats the cycle with the same original data. Then, the checksums are compared again. The positive result of the comparison allows you to continue the system in normal mode.

The input and output the information in the system is controlled to belong physically possible parameter values ​​and the maximum increment of the parameter for a cycle time based interconnection options, sequence a series of events, wait a certain parameter, as a reaction to a specific action, fixing the time after a fixed Events t. e.

Such approaches in the organization of hardware and software for embedded control have been used in almost all modern digital control systems GTD.

Stage production is very important in the implementation of safety-by-design electronic controller. An important role is played by an effective inspection system. Use of the cull, heat, vibration and elektrotrenirovok at the stages of input control elements and the creation of boards, modules and units can significantly improve the reliability of electronic controls, but leads to an increase in the cost of equipment. Control and rejection of chips used can increase reliability by an order.

At the stage of operation, the reliability of the electronic controller may be reduced for objective and subjective reasons. 

 

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