8 analog output function, Analog output function, Status after switching on – Siemens Simatic S7-400 User Manual
Page 543
Interface Submodules
13-47
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
13.7.8
Analog Output Function
Analog Output Function
The 12-bit digital value to be converted is loaded left-justified into the DAC data
registers of the relevant DAC channel. After the data has been written into the
register, digital-analog conversion takes place in the selected channel.
You can see the assignment of the address to the output channels and the
meaning of the data bits in Table.
The data format of the analog output value is a 16-bit value in twos complement.
You can see the representation of the digital output value in Table 13-44.
Table 13-40
Meaning of the Data Bits in the Analog Output Function (IF 961-AIO)
Offset
Address
D15
Writing
D0
Remark
00
H
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
0
0
0
0
DAC data
channel 0
02
H
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
0
0
0
0
DAC data
channel 1
Status After Switching On
Both output channels contain the value “0”.