| Product Type | S7-300 Digital Extension |
| Product Model | 6ES7321-7BH01-0AB0 |
| Supply Voltage Type | DC |
| Product Dimensions | 40 MM × 125 MM × 120 MM |
| Input current | Incoming load voltage L+(no-load), maximum value 90 mA Incoming backplane bus DC 5 V, maximum value 130 mA |
| Weight | 200 g |
32-Channel Digital Input Module for S7-300 Series: Model SM 321, 32×DC 24V, designed for the SIMATIC S7-300 PLC system, provides 32 digital inputs at 24V DC—ideal for large-scale discrete signal acquisition.
High Channel Density: Integrates 32 digital input channels in a single module, reducing the number of modules and rack space required, saving panel space and simplifying wiring.
Supports Sink & Source Input Wiring: Input circuits are compatible with both PNP (source) and NPN (sink) sensors, configurable via jumper or common terminal—offering flexibility for various field device types.
Grouped Electrical Isolation: The 32 input channels are divided into 4 groups of 8 channels each, with galvanic isolation between groups, minimizing crosstalk and improving noise immunity.
Advanced Diagnostics: Supports channel-level diagnostics for wire break and short-circuit detection. Faults are indicated via module LEDs and can be monitored in STEP 7 software for fast troubleshooting and reduced downtime.
Fast Response Time: Typical input delay as low as 0.2 ms, suitable for applications requiring high-speed signal processing.
