SIEMENS S7-300 Ex digital input modules Product Information

Ex digital input modules

Ex digital input modules

  • Digital inputs for signals from the Ex field
  • For the connection of intrinsically safe digital equipment from the Ex field
  • 4 DI NAMUR
  • 4 digital inputs in 4 channel modules (single-channel isolation)
  • Connectable encoder in accordance with EN 60947-5-6 and NAMUR, optionally with wired or unwired mechanical contacts
  • Diagnostics and diagnostics alarm programmable
roduct No. / Product Description Listprice / Your price
6ES7321-7RD00-0AB0
SIMATIC S7, DIGITAL INPUT SM 321, OPTICALLY ISOLATED, 4 DI, 24V DC, NAMUR/DIN 19234, F. SIGNALS F HAZARDOUS AREAS, CAPABLE OF DIAGNOST.,PTB-TESTED

Application

The following intrinsically-safe equipment can be connected to Ex digital input modules:

Ex module

No. of channels

Connectable intrinsically-safe equipment

Digital input

4

Initiators to DIN 19 234 (NAMUR), wired contacts


Design

The Ex digital input modules have the following mechanical features:

  • Compact configuration;
    The rugged plastic housing contains:

    • Green LEDs for each circuit to indicate “1” signal (contact closed or I > 2.1 mA with NAMUR encoders to DIN 19234)
    • Red LED for each circuit to indicate wire break or short circuit
    • Slot for front connector and cable guide, protected by the front cover
    • Labeling area on the front cover.
  • Easy installation:
    The module is mounted on the DIN rail and connected to the adjacent modules via bus connectors.
    There are no slot rules; the addresses of the inputs are predetermined by the slot.
  • User-friendly wiring:
    The modules are wired by means of a plug-in front connector. When they are first plugged in, a coding element clicks into place so that the connector will only fit into modules of the same type. The front connector contains a special barrier for covering the module’s 24 V load current supply. When the module is replaced, the front connector can be used in its fully wired state for the new module of the same type.

Function

Ex digital input modules convert the level of the external binary signals of the intrinsically-safe equipment from the Ex field into the internal signal level of the PLC.

Technical specifications

Article number

6ES7321-7RD00-0AB0

SM321, 4DI, DC24V, HAZARDOUS AREAS

Supply voltage

Load voltage L+

  • ● Rated value (DC)

24 V

  • ● Reverse polarity protection

Yes

Input current

from load voltage L+ (without load), max.

50 mA

from backplane bus 5 V DC, max.

80 mA

Encoder supply

Type of output voltage

via the inputs

Power loss

Power loss, typ.

1.1 W

Digital inputs

Number of NAMUR inputs

4

Input voltage

  • ● Rated value (DC)

8.2 V; from internal power circuit supply

Input current

  • ● on wire-break, max.

0.1 mA

  • ● on short-circuit, max.

8.5 mA

for NAMUR encoders

  • — for signal “0”

0.35 to 1.2 mA

  • — for signal “1”

2.1 to 7 mA

Input delay (for rated value of input voltage)

  • ● Input frequency (with a time delay of 0.1 ms), max.

2 kHz

for NAMUR inputs

  • — Parameterizable

Yes; 0.1 / 0.5 / 3 / 15 / 20 ms (plus 0.25 ms preparation time)

Cable length

  • ● unshielded, max.

200 m

Encoder

Connectable encoders

  • ● NAMUR encoder

Yes; Two-wire connection

Interrupts/diagnostics/status information

Diagnostic functions

Yes

Diagnostic messages

  • ● Diagnostic information readable

Yes

Diagnostics indication LED

  • ● Group error SF (red)

Yes

  • ● Status indicator digital input (green)

Yes

  • ● Channel fault indicator F (red)

Yes

Ex(i) characteristics

Module for Ex(i) protection

Yes

Maximum values of input circuits (per channel)

  • ● Co (permissible external capacity), max.

3 µF

  • ● Io (short-circuit current), max.

14.1 mA

  • ● Lo (permissible external inductivity), max.

100 mH

  • ● Po (power of load), max.

33.7 mW

  • ● Uo (output no-load voltage), max.

10 V

Potential separation

Potential separation digital inputs

  • ● Potential separation digital inputs

Yes

  • ● between the channels, in groups of

1

Standards, approvals, certificates

Use in hazardous areas

  • ● Type of protection acc. to EN 50020 (CENELEC)

[EEx ib] IIC

  • ● Type of protection acc. to FM

Class II, Division 2, Group A, B, C, D T4

  • ● Test number PTB

Ex-96.D.2094X

Ambient conditions

Ambient temperature during operation

  • ● max.

60 °C

Connection method

required front connector

20-pin

Weights

Weight, approx.

230 g