The advantages of INTERBUS Safety

INTERBUS Safety is easy to retrofit in existing automation solutions. The standard controller is replaced with the INTERBUS controller board with integrated safe controller. Depending on the requirements, the user can now operate safe and unsafe devices on one bus line or separate them with a two-cable solution.

In addition to retaining the procedure used for the standard INTERBUS system, the one-bit principle makes it easier to use INTERBUS Safety. The safe electronics module generates a safe bit from the safe peripheral signals. The programmer can now process this safe bit in the programming software SafetyProg by linking it to function blocks.

The diagnostics functions of the standard INTERBUS system are transferred to INTERBUS Safety so that the operator on site knows which safety function has been triggered and why. While the LEDs on the components display I/0 or bus malfunctions, comprehensive information for diagnostics is automatically shown in plain text on the controller and via the diagnostics software Diag+.

As the INTERBUS system permits very short cycle times of 2 to 5 ms due to the data transmission procedure, the process can be switched off within a very short time. Reaction times for INTERBUS can be calculated in detail as the INTERBUS protocol is structured in a deterministic way so that fluctuations in the cycle time do not usually occur.

A defined equation makes it possible to calculate the reaction time of the safe signal from being read in via the input module to being output via the output module. As opposed to other systems, INTERBUS Safety allows the user to specify the switch off times for the safe outputs. This time is used to plan the maximum reaction time of the system that describes the period between detecting a safety request and switching off the danger. With simple project planning and automatic monitoring with the INTERBUS Safety system, this procedure rules out any influence on safety engineering. Alterations to the standard application program or extensions to the fieldbus system, for example, the addition of extra standard components, do not counteract any safety functions.

Internal time switches, the option to control all outputs via fail-safe comparators, monitoring of switching states via pulse output signals and cycle-sensitive inputs, as well the safety protocol, ensure that the probability of residual errors is very low and is below the limits specified in IEC 61508 for SIL3 and EN 954-1 for Cat. 4.