Cyclic Send

The data are automatically sent after expiration of a configurable cycle time (SCANDOWN). This cycle time is indicated in multiples of the task cycle time in which the block is computed. In this operating mode, an overrun error can occur if the transmission is faster than the response time of the receiver. For setpoints, it is necessary to ensure that an acknowledgement is generated by the receiver which is not sent until the setpoint is accepted. The send block is not ready for transmission again until after this acknowledgement has been received.