Siemens CPU 312 - Analog Inputs

Technical data of CPU 31xC
6.6 Technical data of the integrated I/O
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
6-49
6.6.8 Analog inputs
Introduction
This chapter contains the specifications for analog outputs of CPUs 31xC.
The table includes the following CPUs:
• CPU 313C
• CPU 314C-2 DP
• CPU 314C-2 PtP
Technical data
Table 6-14 Technical data of analog inputs
Technical data
Module-specific data
Number of inputs 4 channels with current/voltage input
1 channel with resistance input
Cable length
• Shielded
Max. 100 m
Voltage, currents, potentials
Resistance input
• No-load voltage
Typically 2.5 V
• Measurement current
Typically 1.8 mA to 3.3 mA
Electrical isolation
• Between channels and the backplane bus
Yes
• Between the channels
No
Permitted potential difference
• Between inputs (AI
C
) and M
ANA
(U
CM
)
8.0 VDC
• between M
ANA
and M
internal
(U
ISO
)
75 VDC / 60 VAC
Insulation test voltage 600 VDC
Analog value generation
Measurement principle Actual value encoding (successive
approximation)
Integration time/conversion time/resolution (per channel)
• Configurable
Yes
• Integration time in ms
2,5 / 16,6 / 20
• Permitted input frequency
Max. 400 Hz
• Resolution (including overdrive)
11 bits + signed bit
• Suppression of interference frequency f1
400 / 60 / 50 Hz
Time constant of the input filter 0,38 ms
Basic processing time 1 ms