Graco Modbus TCP Manual page 6

Installation
Rotary Switch
If your system has only one MBTCP module, keep the
rotary switch (S) at its default position of 0.
If the system has multiple MBTCP modules, use a
unique value (position) for each module. Remove the
access cover (E) to set the rotary switch (S) for each
module.
S
E
F . 4
IG
6 334183B