
4
Analog Output
4.1 General
You must only use screened cable when you are connecting analog signals. These
cables reduce the effect of electrical interference. The screen of the analog signal cable
should be grounded at both ends. In situations with different electrical potentials, it is pos-
sible that a current will flow to equalize the potential difference. This current could inter-
fere with the analog signals. Under these circumstances it is advisable to ground the
screen of the signal cable at one end only.
You can use the analog output modules to supply loads and actuators with current or
voltage.
Please take always care of the correct polarity when connecting actua-
tors! Please leave the output clamps of not used channels disconnected
and set the output type of the channel to "deactivated" in the hardware
configurator from Siemens.
The parameterization via CPU, PROFIBUS and PROFINET happens by means of record
sets (DS). The corresponding record set number may be found at the respective module
description. Here also the indices (IX) respectively subindices (SX) for CANopen respec-
tively EtherCAT are listed.
The modules have diagnostics capability. The following errors may release a diagnostic:
n
Error in parameterization
n
Short-circuit recognition
n
Wire-break recognition
Alternated blinking of the channel error LEDs
The alternate blinking of the channel error LEDs of channel 0 and 1 indi-
cates a watchdog error due to a system overload. Restart with a power
cycle your system. If the error occurred again, check configuration and
circuit and adjust them if necessary. If the error persists, please contact
our support.
4.2 Analog value
The analog values are only processed in binary representation. Hereby the binary word
variable is transformed into an analog process signal and put out via the corresponding
channel.
Resolution
Analog value
High byte (byte 0)
Low byte (byte 1)
Bit number
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Resolution
SG
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
12Bit+SG
SG
Analog value (word)
X
X
X
15Bit+SG
SG
Analog value (word)
Cabling for analog signals
Connecting loads and
actuators
Parameterization
Diagnostic functions
Analog value representa-
tion
VIPA System SLIO
Analog Output
Analog value
HB300 | SM-AIO | | en | 17-05
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