I/O Mapping for Network Variables

Safety network variables are transferred by means of the I/O mapping of the safety controller.

The I/O mapping of a safety controller expands depending on the variables configured in the sender (payload) and the maximum number of receivers. To calculate the payload, the Boolean variables configured by the user are combined into bytes, which means that up to 8 Boolean variables require only a 1 byte of payload.

Payload: Every safety network variable list can have a maximum of 32 bytes of payload. This means a maximum of 256 SAFEBOOL variables or a maximum of 16 SAFEINT or SAFEWORD variables, or a combination of them.

Space in the input image: For each safety network variable list (sender): maximum number of receivers * 7 bytes + for each safety network variable list (receiver): <number of bytes of payload> * 2 + 3

Space in the output image: For each safety network variable list (sender): maximum number of receivers * <number of bytes of payload> * 2 + 3 + for each safety network variable list (receiver): 7 bytes of payload

<number of bytes of payload>*2+3: Minimum of 7 bytes for 2 bytes of payload and maximum of 67 bytes for 32 bytes of payload.