CONTREX MLP-Drive - Manual (Page 124)

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Data Inquiry
Use the Data Inquiry to request the current value for Parameters (i.e., Control
Parameters or Monitor Parameters).
Table 3-55 Data Inquiry - Host Transmission
Character # 1 2 3 4 5 6 7 8 9 10 11 12
DEV # DEV # MSG PAR # PAR # DATA DATA DATA DATA DATA
DESC STX 10s 1s TYPE 10s 1s 1000s 100s 10s 1s FORM ETX
ASCII STX 0-9 0-9 2 0-9 0-9 0 0 0 0 0 ETX
The following is a description of the Data Inquiry - Host Transmission Characters.
Character 1 - STX:
This is the first character in the character string. None of the other characters will
be recognized without this character prefix. Always use the ASCII “STX” character;
it enables the MLP-Drives receive buffer.
Characters 2, 3 - Device #:
These characters are the access address of the MLP-Drive. This number identifies
individual MLP-Drives on a mutltidrop system. The MLP-Drive will accept data only
if this number matches the MLP-Drive's address (CP-70), with the exception of a
“00” address. The “00” address is universally accepted by all MLP-Drives that are
on the RS485 Serial Communications Interface.
Character 4 - Message Type:
This character should always be “2”.