9.1. RS communication protocol for LAMBDA DOSER, VIT-FIT, PRECIFLOW, MULTIFLOW, HIFLOW and MAXIFLOW pumps

9.1.1 Format of data sent by the PC to the pump and back

Data sent by the PC: #ss mm a ddd qs c
Data sent back by the pump: <mm ss a ddd qs c
# is the first sign of a command sent by PC
< is the first sign of a message sent by pump
ss is the address of the pump
mm is the address of the PC
a is the command for the sense of rotation:
r for clockwise (cw) rotation (to the right)
l for counter-clockwise (ccw) rotation (to the left) (not for DOSER and MASSFLOW)
ddd is the speed of rotation (3 ASCII numbers from 0 to 9; sent from the highest order digit to the lowest order digit)
qs is the control sum in HEX format (2 ASCII signs of the type 0…9ABCDEF)
c is the end sign cr (carriage return) The pump will fulfill the task and block any manual command on the pump front panel.

9.1.2. Commands not containing data

# ss mm g qs c activates the local command of the pump
# ss mm s qs c the pump is stopped
# ss mm G qs c to send pump data to the PC

9.1.3 Checksum control

The PC sends: #0201r123EEcr

The control sum (checksum) qs is made in the following way (only the last byte (2 ASCII characters of the type 0…9ABCDEF) is taken):

# 0 2 0 1 r 1 2 3 EE (last byte) cr
23 h +30h +32h +30h +31h +72h +31h +32h +33h =1EEh 0Dh

9.1.4 Format of the data transmission

Speed: 2400 Bd (Baud)
8 data bits, odd parity, 1 stop bit