SIEMENS SIMATIC S7-300 SIWAREX U Product Information

SIWAREX U is a versatile weighing module for all simple weighing and force measuring tasks. The compact module can be integrated into SIMATIC automation systems without any problems. Complete data access is possible via the SIMATIC.

Product No. / Product Description S7-300 SIWAREX U Ordering data
7MH4950-1AA01
SIWAREX U WEIGHING ELECTRONICS (SINGLE CHANNEL VERSION) * FOR CONNNECTING ONE SCALE * FOR SIMATIC S7-300 AND ET200M * RS232 INTERFACE FOR CONNECT. OF A PC * TTY INTERFACE FOR REMOTE DISPLAY CONNECTION WITH BUS CONNECTOR
7MH4950-2AA01
SIWAREX U WEIGHING ELECTRONICS (TWO-CHANNEL VERSION) * FOR CONNNECTING TWO SCALES * FOR SIMATIC S7-300 AND ET200M * RS232 INTERFACE FOR CONNECT. OF A PC * TTY INTERFACE FOR REMOTE DISPLAY CONNECTION WITH BUS CONNECTOR
Benefits

SIWAREX U offers the following key advantages:

  • Uniform design technology and consistent communication in SIMATIC
  • Use in distributed plant concept through connection to PROFIBUS DB/PROFINET using ET 200M
  • Measurement of weight or force with a high resolution of 65000 parts and an accuracy of 0.05 %
  • Space saving through use of two-channel version for two scales
  • Direct connection of a remote display to the TTY interface
  • Simple adjustment of scale using the SIWATOOL U program
  • Supports theoretical adjustment without adjustment weights
  • Supports replacement of module without renewed adjustment of scale
  • Can be used in Ex applications
Application

SIWAREX U is the optimum solution wherever strain gage sensors, such as load cells, force sensors or torque measuring shafts, are used for measuring tasks. The typical applications of SIWAREX U are:

  • Fill level monitoring of silos and bunkers
  • Monitoring of loads on cranes and cables
  • Measuring the loading on conveyor belts
  • Overload protection of industrial elevators or rolling mills
  • Balances in hazardous areas (using an Ex interface)
  • Monitoring of belt tension
Design

The SIWAREX U is a compact function module (FM) of the SIMATIC S7-300 and can be snapped directly onto the SIMATIC S7-300 or ET 200M backplane bus. Assembly and wiring are also greatly simplified by using rails with snap-on technology.

The load cells, the power supply and the serial interfaces are connected through the 20-pin standard front plug.

Operation of the SIWAREX U in SIMATIC means that complete integration of the weighing technology into the automation system is provided.

Function

SIWAREX U is available with either one or two measuring channels. One measuring channel is required for each set of scales.

The primary task of SIWAREX U is the measurement of sensor voltage and the conversion of this measurement into a weight value. The signal can also be digitally filtered if required.

As well as determining weights, the SIWAREX MS monitors two freely programmable limits (min./max. as required).

The SIWAREX U comes factory-calibrated. This means that theoretical adjustment of the scale is possible without adjustment weights, and that modules can be replaced without the need to readjust the scale. When using “active bus modules”, replacement is also possible during operation.

Consistent and uniform communication between all system components enables fast, reliable and cost-effective integration and diagnosis in industrial processes.

The SIWAREX U has two serial interfaces. The TTY interface serves to connect up to four digital remote displays. In addition to the two weight values of weighing channels 1 and 2, another two values can be set via SIMATIC and indicated on the remote displays.

A PC for adjusting the scale can be connected through the RS 232 interface.

SIWAREX U can not only be integrated in the plant software using the classic PLC programming languages; STL (Statement List), LD (Ladder Diagram) SFC (Sequential Function Chart) or SCL (Structured Control Language), it can also be integrated by means of graphical configuration with CFCs (Continuous Function Chart), where faceplates are provided in PCS 7 for visualization of the scales.

In contrast to serially linked weighing electronics, SIWAREX U does not need costly additional modules to link it to SIMATIC.

Integration in SIMATIC produces freely-programmable, modular weighing systems which can be modified according to operational requirements.

Using the SIWATOOL U software, the SIWAREX weighing modules can be set up with the convenience of Windows independently of the automation system. Input masks allow all parameters for the weighing modules to be specified, saved and printed for plant documentation.

The diverse diagnostic options provided by SIWATOOL U ensure fast fault locating in online mode.

The SIWAREX U weighing module can be used for potentially explosive areas (zone 2). The load cells can be provided with an intrinsically-safe power supply through an optional Ex interface.

Technical specifications

SIWAREX U

Integration in automation systems

  • S7-300

Direct integration

  • S7-1500

Through ET 200M

  • S7-400 (H)

Through ET 200M

  • PCS 7 (H)

Through ET 200M

  • Automation systems from other vendors

Through ET 200M

  • Stand-alone (without SIMATIC CPU)

Possible with IM 153-1

Communication interfaces

  • SIMATIC S7 (P bus)
  • RS 232
  • TTY

Connection of remote displays
(through TTY serial interface)

Gross, channel 1, 2 or default value 1, 2

Adjustment of scales settings

Through SIMATIC (P bus) or PC using SIWATOOL U (RS 232)

Measuring properties

Error limit to DIN 1319-1 of full-scale value at 20 °C ± 10 K (68 °F ± 10 K)

0.05%

Internal resolution ADC
Data format of weight values

65535
2 byte (fixed-point)

Number of measurements/second

50

Digital filter

0.05 … 5 Hz (in 7 steps), mean value filter

Weighing functions

Weight values

Gross

Limit values

2 (min./max.)

Zero setting function

Per command

Load cells

Strain gages in 4-wire or 6-wire system

Load cell powering

Supply voltage Us (rated value)

6 V DC1)

Max. supply current

≤ 150 mA per channel

Permissible load resistance

  • RLmin

> 40 Ω per channel

  • RLmax

< 4010 Ω

With Ex(i) interface

  • RLmin

> 87 Ω per channel

  • RLmax

< 4010 Ω

Permissible load cell characteristic

Up to 4 mV/V

Max. distance of load cells

500 m2)
150/500 m for gas group IIC

500 m2) for gas group IIB (see SIWAREX IS Manual)

Intrinsically-safe load cell powering

Optional (Ex interface) with SIWAREX IS

Auxiliary power supply

Rated voltage

24 V DC

Max. power consumption

150 mA (single-channel) / 240 mA (dual-channel)

Current consumption on backplane bus

≤ 100 mA

Certification

ATEX 95, FM, cULUS Haz. Loc.

IP degree of protection to DIN EN 60529; IEC 60529

IP20

Climatic requirements

Tmin (IND) to Tmax (IND)) (operating temperature)

  • Horizontal installation

0 … +60 °C (32 … 140 °F)

  • Vertical installation

0 … +40 °C (32 … 104 °F)

EMC requirements according to

according to NAMUR NE21, Part 1; EN 61326

Dimensions

40 x 125 x 130 mm (1.58 x 4.92 x 5.12 in)