Siemens SIMATIC S7-300 Reference Manual page 399

Output Addresses
The following channel addresses apply to the module outputs:
Chan-
nel
0
1
4.30.2 Measuring/output method and measuring/output range of the
SM 334; AI 4/AO 2 x 8/8 bits
You cannot program the SM 334; AI 4/AO 2 x 8/8 bits.
Selecting the Measurement Method and the Type of Output
Select the measuring method of an input channel (voltage, current) by wiring the
input channel appropriately.
Select the type of output of an output channel (voltage, current) by wiring the
output channel appropriately.
Unused Channels
You must short-circuit unused input channels and you should connect them to
M . In this way, you obtain an optimum noise immunity for the analog module.
ANA
Unused output channels must be left open.
Measuring ranges
The SM 334; AI 4/AO 2 x 8/8 bits has the measuring ranges 0 to 10 V and 0 to 20
mA.
Unlike the other analog modules, the SM 334 has a lower resolution and no
negative measuring ranges. Take this into account when you read measured value
tables 4-10 and 4-14 on pages 4-13 and 4-15.
Output ranges
The SM 334; AI 4/AO 2 x 8/8 bits has the output ranges 0 to 10 V and 0 to 20 mA.
Unlike the other analog modules, the SM 334 has a lower resolution the analog
outputs do not have underranges. Take this into account when you read tables
4-35 and 4-37 on pages 4-26 and 4-27.
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Initial module address
Module start address + 2 bytes address offset
Address
Analog Modules
4-193