SIWAREX WP231 – Weighing Electronics Module – Siemens Modules

Article Number

7MH4960-2AA01

Integration in automation systems

S7-1200

SIMATIC S7‑1200 system bus

Operator panel and/or automation systems from other vendors

Via Ethernet (Modbus TCP/IP) or RS 485 (Modbus RTU)

Communication interfaces

• SIMATIC S7‑1200 backplane bus
• RS 485 (Modbus RTU, Siebert remote display)
• Ethernet (SIWATOOL V7, Modbus TCP/IP)
• Analog output 0/4 … 20 mA
• 4 × digital outputs 24 V DC, floating, short-circuit proof
• 4 × digital inputs 24 V DC, floating

Commissioning options

• Using SIWATOOL V7
• Using function block in SIMATIC S7‑1200 CPU / Touch Panel
• Using Modbus TCP/IP
• Using Modbus RTU

Measuring accuracy

EC type approval as non-automatic weighing instrument, trade class III

3000 d ≥ 0.5 μV/e

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

0.05%

Internal resolution

Up to ± 4 million parts

Measuring frequency

100 / 120 Hz

Digital filter

Variable adjustable low-pass and average filter

Typical applications

• Non-automatic weighing instruments
• Force measurements
• Fill-level monitoring
• Belt tension monitors

Weighing functions

Weight values

• Gross
• Net
• Tare

Limit values

• 2 × min/max
• Empty

Zeroing

Per command

Tare

Per command

Tare specification

Per command

Load cells

Full-bridge strain gauges in 4-wire or 6-wire system

Load cell powering

Supply voltage (regulated via feedback)

4.85 V DC

Permissible load resistance

• R_Lmin

> 40 Ω

• R_Lmax

< 4 100 Ω

With SIWAREX IS Ex interface

• R_Lmin

> 50 Ω

• R_Lmax

< 4 100 Ω

Load cell characteristic

1 … 4 mV/V

Permissible range of the measurement signal (with 4 mV/V sensors)

-21.3 … +21.3 mV

Max. distance of load cells

500 m (229.66 ft)

Connection to load cells in Ex zone 1

Optionally via SIWAREX IS Ex interface (compatibility of the load cells must be checked)

Approvals/certificates

• ATEX Zone 2
• UL
• EAC
• KCC
• RCM
• OIML R76
• Type approval 2009/23/EC (NAWI)

Calibration approval

EC type approval OIML R76

Auxiliary power supply

Rated voltage

24 V DC

Max. power consumption

200 mA

Max. power consumption SIMATIC Bus

3 mA

IP degree of protection to EN 60529; IEC 60529

IP20

Climatic requirements

T _min (IND) … T_max(IND) (operating temperature)

• Vertical installation

-10 … +40 °C (14 … 104 °F)

• Horizontal installation

-10 … +55 °C (14 … 131 °F)

EMC requirements

According to EN 45501

Dimensions

70 × 75 × 100 mm (2.76 × 2.95 × 3.94 inch)