Instruction manual

PROTOCOL
Protocol refers to the format, sequence and value of the data fields utilized in Host Mode communication
messages. Each data field of a CompuScale III message contains one or more bytes of ASCII binary code.
Each byte contains:
» 8 data bits
» no parity bit
» 1 stop bit
DATA FIELD DESCRIPTIONS
The following data fields are utilized in CompuScale III, host mode messages.
som
CompuScale III start of message, ASCII character = STX (Hex Value = 02).
DEVICE
Identifies the CompuScale III to which the message applies. The device number equals the Unit I.D. code, as
set by SW1 contacts 1 - 4. ASCII characters = 00 to 15.
MT
Identifies the message type transmitted, ASCII characters:
50 = material flow rate
51 = material load
52 = belt speed
53 = totalized material
READING
Contains the measurement value in the engineering units of measure selected during CompuScale III
programming. The number of bytes in this data field will vary dependent upon the reading value. Up to 8
ASCII characters including the decimal point may be transmitted.
UNITS
Three ASCII characters identify the totalizer engineering units (MT = 53 only). The first character is always a
space. The remaining characters may be:
t = Tonnes
T = Tons
LT = Long Tons
kg = Kilograms
lb = Pounds
eom
CompuScale III end of message, ASCII character = CR (Hex Value = 0D).
+20 mA
-20 mA
0
s12345678s
tsnrtttttt
at ddhhhhho
rp
t
PL-367 10 – 3