Specifications

1070 072 131-102 (96.08) GB
BUEP03E Protocol 8-5
8.5 Transmission Sequence
8.5.1 Receiving Characters
Two different receive modes can be specified by the Receive Mode
command.
a) Unrestricted Receive: The user defines a PLC Receive buffer (max.
256 bytes) on the PLC side. When the Receive command activates
communication via R5REQ, all characters are received and filed in the
BÜP03E Receive buffer until
- the monitoring time overflows
- or the job is terminated
- or the Receive-data length has been reached.
Unrestricted Receive also facilitates communication with the peripherals
which have variable protocol.
A practical case: BÜP03E should Receive-data from a code reader.
However, the code reader transmits the data with a start identifier only du-
ring the first transmission. If the transmission has to be repeated, the start
identifier would be missing. In practice, this means that the protocol se-
quences are not always uniform.
In such a case, the user can receive all the characters and react accor-
dingly, as indicated on Page 8-30 - Example 1.
b) Conditional Receive: Receive Mode parameters, such as start and
end identifiers, termination characters and Receive-data length, can also
be specified by the Receive Mode command. If these identifiers are reco-
gnised in the data flow, the appropriate response is implemented. All re-
ceived characters (even the control characters) are received in the
BÜP03E Receive buffer.
The Data Copy command copies all data from the BÜP03E Receive buf-
fer into the PLC Receive buffer for interpretation by the user.