Product Overview
Applications
Receives DC signals through 16 digital inputs using the stated signal thresholds.
Technical Summary
| Product type | SIMATIC S7-300 SM 321 isolated digital input module |
|---|---|
| Digital inputs | 16 |
| Input voltage | 48 V rated; 48 V DC to 125 V DC |
| Signal "0" | -146 V DC to +15 V DC |
| Signal "1" | 30 V DC to 146 V DC |
| Front connector | 20-pin |
| Backplane bus current | 40 mA maximum from 5 V DC |
| Diagnostics | No diagnostics function, diagnostic alarm, hardware interrupt, or group error SF indication |
Key Features
16 isolated digital inputs with IEC 61131 type 1 input characteristic curve.
DC input voltage: 48 V rated value; 48 V DC to 125 V DC.
Signal "0": -146 V DC to +15 V DC; signal "1": 30 V DC to 146 V DC.
Required front connector: 20-pin.
Digital inputs are isolated from the backplane bus by an optocoupler; isolation between channels is provided in groups of 8. Horizontal installation supports 8 up to 40 °C, and vertical installation supports 8 up to 40 °C.
Spare part; Product cancellation. Dimensions are 40 mm width, 125 mm height, and 120 mm depth; approximate weight is 200 g.
Frequently Asked Questions
What is the exact product type and input capacity?
It is the Siemens 6ES7321-1CH20-0AA0 SIMATIC S7-300 SM 321 isolated digital input module with 16 digital inputs.
What input voltage does this module use?
The input voltage is DC, with a rated value of 48 V and a stated range of 48 V DC to 125 V DC.
Which connector is required?
The required front connector is 20-pin.
Does it provide channel and backplane isolation?
The digital inputs are not isolated between individual channels; isolation is provided in groups of 8. They are isolated from the backplane bus by an optocoupler.
