Baumer BA ZADM023 - Handbuch (Seite 75)

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12.3 Protocol mode
This mode allows multi sensor configurations with one master.
Protocol sequence:
In this operating mode, the sensor is always the slave. Every command starts with an ENQ followed by the sensor’s
address. The sensors response to ENQ is ACK. Next, the master sends data between STX and ETX. The data con-
tains the actual command and, if required, parameters. If the command sent by the master initiates an action, the
sensor responds with ENQ followed by its own address. The master then responds with an ACK and the sensor starts
transmitting the answer between STX and ETX.
example: Master sends a command which initiates a response from the sensor
Master sends delay Sensor with address ‘2’ sends
ENQ ‘2’
T1 (Time between ENQ from master and ACK from
sensor)
ACK
T2 (Time between ACK and data transmission to the
sensor)
STX <data> ETX
T3 (Time between data transmission from master and
ENQ from sensor)
ENQ ‘2‘
T4 (Time between ENQ from sensor and ACK from
master)
ACK
T5 (Time between ACK from master and data transmis-
sion from sensor)
STX <data> ETX