Burster 9180, Manual

Page: 80 / 109

Model 9180
burster
Digital Panelmeter
Page 4-36
Protocol ISO 1745
For the word format, 1 start bit, 7 data bits, 1 parity bit and 1 stop bit are needed.
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Sending messages to the device
SOH D d STX C C X ............... X ETX BCC
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One SOH byte for the beginning of the message [ASCII 01].
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One byte for the tens digit and one byte for the ones digit of the device address to be targeted.
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One STX byte signifying text beginning [ASCII 02].
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Two command bytes in accordance with the function table.
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For commands to change parameters one block of n-bytes for the numerical value including
decimal point.
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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:
Performance of an Exclusive-OR for all bytes between STX (not included) and ETX
(included)
- If the byte lies in ASCII code at
≥
32 it can be used as BCC control byte.
- If the byte lies in ASCII code at < 32 you obtain the BCC control byte by adding 32.
Example:
Protocol ISO 1745
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Messages received by the device
The typical message format which a device supplies as a response to a command from a
master unit, appears as follows:
1. For commands requesting 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 ( D = tens digit, d = ones digit ).
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One STX byte for beginning the text [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 signifying end of text [ASCII 03].
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One control byte computed as above.
If the master unit transmits a message with the address 00, the command is interpreted by all the
devices in the network and you obtain a response.