General Information

Library Overview

The XpsuSupport library provides the function blocks FB_XpsuDiag and FB_XpsuMain for diagnostics and maintenance purposes with XPSU safety modules.

XPSU safety modules generate bit sequences that are available at the non-safety-related output Z1. The bit sequences encode diagnostics information relating to the XPSU safety module. Refer to the user guide of your XPSU safety module for details on the output Z1, Related Documents.

If the output Z1 is connected to a controller or to other suitable equipment, the bit sequence can be used as input information for the function block FB_XpsuDiag. The function block FB_XpsuDiag decodes the bit sequence provided by the XPSU safety module and outputs a diagnostics code.

This diagnostics code can be made available to the function block FB_XpsuMain.

The function block FB_XpsuMain provides counters that let you track and manage maintenance and service life requirements for the XPSU safety module itself as well as connected equipment such as sensors, command devices, and actuators:

• Counters for cycles of the safety-related inputs

• Counters for cycles of the safety-related outputs

• Counter for cycles of the safety module itself

In addition, the function block can be used to monitor and manage the due dates of proof tests required for the safety-related function and/or the equipment used to implement it.

General Considerations

The bit sequence generated by the XPSU safety module consists of 10 bits. The bit duration set at the input i_timBitDuration of the function block FB_XpsuDiag must be supported by the bit duration of the connected XPSU safety module. Refer to the user guide of your XPSU safety module for details, Related Documents. For correct detection of the full bit sequence, the cycle time of the task that executes the function blocks must be less than or equal to the signal duration of one bit divided by four. For example, if the bit duration is set to 200 ms, the cycle time must be less than or equal to 50 ms.

Both function blocks of the library must be used in a cyclic task and executed in each cycle of their task.

The duration of the full bit sequence is ten times the adjusted bit duration. Changes in state (for example, deactivation of a safety-related input of the XPSU safety module) during a running sequence are transmitted in the subsequent sequence. If such changes in state do not persist until the next sequence starts (for example, if a safety-related input is deactivated and activated within the duration of a single bit sequence), they are not encoded in this bit sequence. In such a case, they cannot be detected by the function block FB_XpsuDiag. As a consequence, the corresponding cycle counter is not increased by the function block FB_XpsuMain.

If several devices are connected to the safety-related inputs of an XPSUDN or an XPSUS safety module, the cycle counter may miss cycles under the following condition: If one connected device has deactivated a safety-related input and not yet reactivated it, and if other devices connected to other safety-related inputs perform switching operations in the meantime.

Removing power to the XPSU safety module is detected by the library with a delay of up to eight seconds.

Removing power to the XPSU safety module may cause the function block FB_XpsuDiag to detect information that is incorrect on the state of the XPSU safety module.

Characteristics of the Library