Siemens Simatic S7-400 - Manual (Page 605)

List of Abbreviations
E-3
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
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
CM
Common mode voltage
U
H
Auxiliary voltage
U
iso
Potential difference between M
ANA
and local ground
UC Universal current
UR Universal rack
USR USR
Vs Sensor voltage
VZ Sign