Siemens 6ES7231-4HD50-0XB0 SIMATIC S7-1200 SB 1231 4AI 14-Bit Signal Board PLC I/O Module

The Siemens 6ES7231-4HD50-0XB0 SB 1231 is a signal board for the SIMATIC S7-1200 that adds 4 analog inputs with 13-bit plus sign resolution, selectable for +/-10V, +/-5V, +/-2.5V, or 0/4-20 mA per channel. It draws 24 V DC at 30 mA and mounts directly on the CPU faceplate without a backplane slot.

Technical Specifications

Certifications & Standards

• CE
• UL
• cULus
• RCM
• KC

Selection Notes

13-bit-plus-sign resolution across four switchable voltage or current ranges lets the same board read a 4-20 mA pressure transmitter on one channel and a +/-10V load cell amplifier on another, without separate hardware per signal type. Wire-break detection on the current ranges flags a disconnected 4-20 mA loop as a diagnostic alarm rather than a silent zero reading. Because it occupies the CPU's signal-board slot rather than a backplane position, adding analog sensing this way leaves the backplane's SM slots free for higher-channel-count I/O modules.

Applications

Low-channel-count analog sensing (temperature, pressure, level, load) on SIMATIC S7-1200 CPUs where a full SM 1234-class analog module isn't justified by the point count.