Siemens sitrans LU01 - Manual (Page 101)

7ML19985BE02 SITRANS LU01 – INSTRUCTION MANUAL Page 95
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26 through 32. The mode of communication is established by the configuration of the
connection made at the SITRANS LU01, either RS-232, RS-485 or bipolar current loop.
The SITRANS LU01 uses simplex convention communication protocol. Data messages
are continuously transmitted at regular intervals (no poll is required) at 4800 baud. All
data is transmitted in structured messages of ASCII characters consisting of 8 data bits,
no parity, and 1 stop bit.
If Peripheral Communications (P740) is set for "formatted" messages, a comma is inserted
between each message field (except immediately preceding the "End of Message"
characters).
MT-00 Measurement Message
Status A
1 character, $0 to $F (convert to binary, e.g. temp, echo, and cable OK, not priority)
Field Name Definition
Start Of Message STX ($02)
Message Type
2 characters, 00 (indicates the following data pertains to a scan point mea-
surement)
Point # 3 characters, 001 to 003 (e.g. the message pertains to Point Number 1)
Reading
5 characters, 0.000 to 9999. (e.g. reading = 678.9, DDDD. = no data, EEEE. =
overflow)
start of message point # status A status C percent
message type reading status B temperature end of message
# # # #
1 = temp alarm
1 = loss of echo (failsafe expired)
1 = transducer cable fault
1 = priority point
MSB LSB