Burster 9180, Manual

Page: 69 / 109

burster
Digital Panelmeter
Model 9180
Page 4-25
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One ETX byte for end of text [ASCII 03].
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One BCC control byte is computed as follows:
When executing an Exclusive-OR operation for all bytes between STX (not included) and ETX
(included)
- If the byte in ASCII code lies at ≥ 32 it can be used as a BCC control byte.
- If the byte in ASCII code lies at < 32 you obtain the BCC control byte by adding 32.
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Receiving messages from the device
The typical message format, which the device supplies as a response to a command,
appears as follows:
1. Commands which require a value:
SOH D d STX X ............... X ETX BCC
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One SOH byte for the beginning of a message [ASCII 01].
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2 address bytes.
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One STX byte for text beginning [ASCII 02].
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n-bytes corresponding to the desired value (including symbols and decimal point).
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One ETX byte for end of text [ASCII 03].
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One BCC control byte computed in accordance with the information above.
If the master unit transmits a message to the address 00, the command is interpreted by all the devices
in the network and no response is obtained.
2. Commands requiring no value:
D d ACK or D d NAK
The device transmits an acknowledgement that the message has been received.
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If the message was not correctly received and interpreted, the response consists of two address
bytes and one "ACK" byte [ASCII 06].
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If the received message was not recognized and errors have arisen, the response consists of
two address bytes and one "NAK" byte [ASCII 21].
If the master unit transmits a message to the address 00, the command is interpreted by all the devices
in the network and a response is obtained.