simatic s7-300 - megaelektrik.net

4
SIMATIC S7-300
Analog modules
SM 335 fast analog I/O module
■ Overview
• High-speed analog inputs and outputs for the SIMATIC
S7-300
• For the connection of ana log sensors and actuators
• The SM 335 fast analog in put/output module provides:
• 4 fast analog inputs
(basic conversion time for 4 channels max. 1 ms)
• 4 fast analog outputs
(conversion max. 0.8 ms per channel)
• Encoder power supply 10 V/25 mA
• 1 counter input (24 V/500 Hz)
• The SM 335 has two special modes:
• Comparator: In this mode the SM 335 compares a setpoint
value with an analog value measured at the analog input.
Application: very fast comparison of an analog value
• Measurement only: In the „measurement only“ mode, the
analog inputs are measured continually without updating the
analog outputs.
Application: very fast measurement of analog values
(< 0.5 ms)
■ Technical specifications
Module-specific data
Number of inputs 4
Number of outputs 4
Cable length, shielded
200 m
With wire-break monitoring in range 30 m
0 V ... 10 V
Voltages, currents, potentials
Rated load voltage
24 V DC
Polarity reversal protection
yes
Galvanic isolation
yes
Permissible potential difference
• between inputs (U CM )
3V
• between input (M terminal) and 75 V DC
central grounding point
• Insulation
tested at 500 V DC
Current consumption
• from S7-300 backplane bus, max. 75 mA
• from L+, max.
150 mA
Power losses, max.
3.6 W
Status, interrupts, diagnostics
Interrupts
• Limit value interrupt
no
• Cycle end interrupt
yes, parameterizable
• Diagnostics interrupt
yes, parameterizable
Diagnostic functions
• Fault display for grouped fault yes, red LED
• Diagnostic information can be yes
read out
Analog value generation
for inputs
Measuring principle
successive approximation
Conversion time per channel 200 µs
• Basic conversion time for
1ms
4 channels, max.
Resolution
• Bipolar
13 Bit + Vorzeichen
• Unipolar
14 Bit
Analog inputs
Interference between inputs
• at 50 Hz
65 dB
• at 60 Hz
65 dB
Operational limits
(over entire temperature range,
referred to input range)
• with voltage measurement ± 0.15% (with 14-bit resolution)
• with current measurement 0.25%
Basic error limit
0.13% (with 14-bit resolution)
(operational limits at 25 °C,
referred to input range)
Temperature error
± 0.1% (with 14-bit resolution)
(referred to input range)
Linearity error
± 0.015%
(referred to input range)
Repeatability (under steady-state ± 0.05%
conditions, at 25 °C, referred to
input range)
Encoder selection data
Input range (rated values)/input
resistance
•Voltage ± 1V; ± 10 V; ± 2.5 V; 0 V ... 2 V;
0 V ... 10 V: 10 MΩ
• Current (max. 2 channels programmable
as current inputs)
Permissible input voltage for voltage
input (destruction limit)
Permissible input current for current
input (destruction limit)
Connection of signal encoder
• for voltage measurement
• for current measurement
± 10 mA; 0 mA ... 20 mA;
4 mA ... 20 mA: 100 Ω
± 30 V
25 mA
possible
- as 2-wire transducer not possible
- as 4-wire transducer possible
• for resistance measurement not possible
Output for supplying the transducer
10 V/25 mA
(short-circuit
proof)
4/72 Siemens ST 70 · 2005