Siemens Simatic M7-400 Reference Manual page 605

S + Sensor lead (positive)
S – Sensor lead (negative)
SCL Structured control language
SP Sensor power
SF "Group error" LED
SFB System function block
SFC System function
SM Signal module
SSI Synchronous serial interface
SSL System status list
STL Statement list
TD Text display
TR Transducer
U Common mode voltage
CM
U Auxiliary voltage
H
U Potential difference between M
iso
UC Universal current
UR Universal rack
USR USR
Vs Sensor voltage
VZ Sign
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
and local ground
ANA
List of Abbreviations
E-3