6ES7331-7KF02-0AB0

Product information

The 6ES7331-7KF02-0AB0 is a Siemens SIMATIC S7-300 analog input module: SM 331, isolated, 8 AI, with selectable resolution of 9 / 12 / 14 bits supporting voltage, current, thermocouple and resistance measurement. Four of the eight channels can be used for resistance measurement. Alarm and diagnostics functions are included, and modules can be removed or inserted with the backplane bus active.

Because one module covers voltage, current, thermocouple and resistance signals, it is a common choice where an installation mixes measurement types and the channel configuration is set by wiring and parameterisation rather than by module type.

Technical specifications

Manufacturer / family	Siemens · SIMATIC S7-300
Product type	SM 331, analog input, isolated
Number of analog inputs	8
Channels usable for resistance measurement	4
Resolution	9 / 12 / 14 bits, selectable
Signal types	Voltage, current, thermocouple, resistance
Constant measuring current (resistance)	1.67 mA typical
Permissible input voltage (destruction limit)	20 V continuous · 75 V for max. 1 s (mark-to-space ratio 1:20)
Permissible input current (destruction limit)	40 mA
Load voltage L+	24 V DC, reverse polarity protected
Current from load voltage (no load)	Max. 30 mA
Current from backplane bus	Max. 50 mA at 5 V DC
Power loss	1 W typical
Diagnostics	Alarm and diagnostics functions
Removal/insertion under backplane bus voltage	Yes

Specifications as published in Siemens product data for this article number. Verify against the nameplate of the unit offered to you.

Lifecycle status

Siemens product data identifies this article number as a spare part. Channel configuration is set by wiring and by the engineering project rather than by a fixed module type, so a replacement should be matched on the complete ordering code — several SM 331 variants exist with different channel counts and resolution.

Typical applications

• Analog measurement where voltage, current, thermocouple and resistance signals coexist in one rack
• Process measurement on S7-300 installations — pressure, flow, level and temperature transmitters
• Applications benefiting from module diagnostics and alarm reporting
• Spare-part replacement on existing installations

Application examples describe typical uses of this product type. Suitability for your own installation must be confirmed against your engineering documentation.

Related references

• 6ES7332-5HD01-0AB0 — SM 332 analog output module, 4 AO
• 6ES7321-1BH02-0AA0 — SM 321 digital input module, 16 DI
• 6ES7231-5PF32-0XB0 — S7-1200 SM 1231 RTD module, 8 resistance-thermometer inputs

Before you order

To confirm a specific unit, please provide the complete ordering code, a nameplate photograph, the quantity required and the delivery destination. Availability, condition, quantity, lead time and commercial terms are confirmed individually after inquiry.

Frequently asked questions

Which signal types does this module accept?
Voltage, current, thermocouple and resistance signals, with resolution selectable between 9, 12 and 14 bits.

Can all eight channels measure resistance?
Four of the eight channels can be used for resistance measurement.

Does it supply the measuring current for resistance sensors?
Yes, with a typical constant measuring current of 1.67 mA.

Can the module be swapped with the rack powered?
Siemens states removal and insertion with active backplane bus is possible. Follow the current manual for the procedure and any restrictions.

What is the price and lead time?
Confirmed individually against current availability and quantity.