<< Click to Display Table of Contents >> Navigation:  »No topics above this level« Timing

mapp Services V5.16

PGNs must be received or transmitted in a specific cycle time so that information can be transmitted or received.

For example, PGN DM01 must be received or transmitted at least every 1000 ms. If the PGN is received in a slower cycle time such as 3000 ms, the PGN is received, but the status of the PGN indicates that the PGN was received in the wrong cycle time (mpJ1939_PGN_ERROR_CYCLE_TIME).

If PGN DM01 is queried in a faster cycle time such as 10 ms, this is no problem. No error occurs during reception. PGN DM01 is nevertheless only received/transmitted in 1000 ms.

If PGN DM01 is received via function block MpJ1939Generic, this function block must be in a task class ≤1000 ms.

The status of the received/transmitted PGN can be read from parameter Status of the provided variable.

If different PGNs are to be received/transmitted, they can be called in a task class that contains the fastest cycle time for a PGN. If PGNs TSC1, DM1 and CCVS1 are used, all PGNs necessary for PGN TSC1 can be queried with a cycle time of 10 ms. It is important here that PGN DM1 is nevertheless only automatically received/transmitted every 1000 ms, for example, since this is the cycle time of the PGN.

The following cycle times must be observed for PGNs that can be defined in the MpJ1939Generic configuration:

For PGNs that are not provided in the MpJ1939Generic configuration, information regarding cycle time can be taken from the J1939 standard. For more information, see here.