8. SMA protocol | 107
8 SMA protocol
8.1 General description
The protocol of the "Scale Manufacturers Association" (SMA) provides a sim
ple access to the scale. It can be used for reading data, or for executing func
tions.
The RS-485 interface is used as an interface.
Fixed interface settings are 8 bits, no parity and 1 stop bit.
The commands to the transmitter are printable ASCII characters starting with
<LF> = 0A hex and ending with <CR> = 0D hex.
The transmitter sends a reply on each received command after ap
prox. 100 ms. With commands that wait for standstill of the weight value, the
reply can be delayed by the timeout.
The following commands are supported:
W, Z, D, A, B, <ESC>, H, P, Q, R, S, T, M, C, I, N
