EUCHNER HBLS 072725 - Handbuch (Seite 32)

EUCHNER Pendant station HBLS 072725
067018-08-01/06 Subject to technical modifications page 10 / 22
8. Data Transfer
8.1 Protocol 3964 R
The protocol of the serial interface is leant to the procedure 3964 R.
The data transfer starts by sending the STX character. The receiver has to respond within
128 ms with the DLE character. The transmitter will then send the information.
The connection will not be made if the receiver responds with NAK, a character <> DLE, an
incorrect character, or if the response isn’t in the proper time frame. The receiver will stop the
data transfer after 3 unsuccessful attempts, and will then send a failure message (HBLS will
show situation with all LEDs flashing).
When the receiver responds within allotted time frame with the DLE character, the data of the
transmitter buffer will be sent to the receiver. The receiver itself is expecting the data within
128 ms. If the data is not sent within this time, the receiver will send the NAK character. The
transmitter will then try to send the telegram again. The transmitter will stop the data transfer
after 3 unsuccessful attempts, and will then send a failure message (HBLS will show
situation with all LEDs flashing).
After sending the content of the buffer, the transmitter will add the DLE and ETX character as
an acknowledgement. In addition to this, the transmitter will send the BCC character
(Block Check Character).
The receiver will respond within 128 ms with the DLE character to confirm the successful
data transmission, or will send the NAK character if an unsuccessful transmission has
occurred.