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5.2
Communication Protocols
The scale has two communication protocols, escape and maintenance protocol.
5.2.1
Escape Protocol
An escape protocol is where the escape (0X1B or ASCII 27) is used to indicate that there is a command following. On the PC
side there must be a listener created by the vendor that will interpret this protocol. This listener must also take care of all the
issues regarding data integrity to make sure that the data that was sent and received is valid.
Two examples include:
• Scale initiated communication
• PC initiated communication
The escape protocol commands table shows (below) what can be sent across communications lines.
ESC characters that will be used is shown below.
ESC
Name
Character
R
Reading
W
Weight
Height
H
BMI
B
Units
N
End of Packet (EOP)
E
Diagnostics
A
(request)
Diagnostics
Z
(response)
C
Control (set a value)
PC Initiated
Request current values/settings
Diagnostics
Send scale control messages
PC Initiated
Send single reading
Send diagnostic response
Table 5-2. Escape Protocol Commands
ESC Value with
Parameters
R
Tells PC the scale is sending a reading; immediately following this is the value that is sent
Example: <ESC><R>ESC><W0200.0<ESC>Nm<ESC>E
Wnnn.n
The patient weight (Example: W02000 means 200.0). If scale is overloaded or under loaded,
999.99 is returned
Hnnn.n
Patient height
Bnn.n
Patient BMI
Nc
Indicates the units the values have been taken (m=metric, c=constitutional).
E
Indicates the end of the command has been reached.
Accc
A request for a diagnostic test on certain parts of the scale (like battery life, load cells).
Zccc
The response of the diagnostics done on the scale; values include error codes to indicate an
issue, or all zeros (Z000) to indicate the scale is performing properly
Cccc=c
Sets the value of the scale's global settings
Example: <ESC><CUOM=m><ESC><E sets the unit of measurement
Table 5-3. ESC Characters
Name of Control
Unit of Measure (metric or constitutional)
Table 5-4. Scale Global Values and Identifiers
© Rice Lake Weighing Systems ● All Rights Reserved
ESC Value
R
A
C
ESC Value
R
Description
Identifier
Unit
UOM
c (m or c)
Communication
17
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