SIEMENS 6ES7321-1EH01-0AA0 32-Channel 24VDC Digital Input Module | Replacement, Equivalent & Selection Guide
The SIEMENS 6ES7321-1EH01-0AA0 is a 32-channel digital input module designed for the SIMATIC S7-300 programmable logic controller (PLC) series. It accepts 24 VDC signals and is widely deployed in industrial automation, process control, and machine safety applications. This page provides a comprehensive selection guide, compatible replacement options, and sourcing information for engineers and procurement teams.
Technical Specifications
- Part Number: 6ES7321-1EH01-0AA0
- Series: SIMATIC S7-300
- Module Type: Digital Input (DI)
- Number of Inputs: 32 channels
- Input Voltage: 24 VDC
- Input Current: Approx. 7 mA per channel
- Signal Groups: 4 groups × 8 channels
- Isolation: Optocoupler isolation between field and backplane
- Backplane Bus: S7-300 standard backplane
- Dimensions (W×H×D): 40 × 125 × 120 mm
- Weight: Approx. 240 g
- Operating Temperature: 0 °C to +60 °C
- Storage Temperature: −40 °C to +70 °C
- Degree of Protection: IP20
- Standards: CE, UL, cULus, ATEX (Zone 2)
Compatible Replacement & Equivalent Models
When the 6ES7321-1EH01-0AA0 is unavailable or discontinued, the following models are functionally compatible or serve as direct replacements:
- 6ES7321-1EH02-0AA0 — Successor revision; pin-compatible, same 32-channel 24 VDC DI specification, updated firmware support
- 6ES7321-1BH02-0AA0 — 16-channel 24 VDC DI; suitable when channel count can be halved with two modules
- 6ES7321-1FF01-0AA0 — 8-channel 120/230 VAC DI; use when field signals are AC rather than DC
- 6ES7321-1CH20-0AA0 — 16-channel 24 VDC DI with diagnostic interrupt; upgrade path for fault-detection requirements
- Third-party equivalents: Certain compatible S7-300 DI modules from approved OEM partners may be evaluated on a project basis — contact Konmask for assessment
Why Choose the Original Model
- Guaranteed compatibility with all S7-300 CPUs (CPU 312 through CPU 319) and existing STEP 7 / TIA Portal configurations
- Proven field reliability across millions of installed units in automotive, chemical, and utilities sectors
- No re-engineering required — drop-in replacement for existing racks without hardware or software modification
- Full SIEMENS warranty and lifecycle support when sourced through authorized channels
- ATEX Zone 2 certification for use in potentially explosive atmospheres
Typical Applications
- Discrete signal acquisition from pushbuttons, limit switches, and proximity sensors
- Machine tool and conveyor line control panels
- Building automation and HVAC monitoring
- Water treatment and utilities SCADA integration
- Automotive assembly line safety interlocks
- Pharmaceutical and food & beverage process lines (with appropriate enclosure)
System Compatibility
- PLC Platform: SIMATIC S7-300 (all standard and fail-safe CPUs)
- Programming Software: SIEMENS STEP 7 v5.x, TIA Portal V13 and above
- Racks: UR1, UR2, ER1, ER2 expansion racks
- Power Supply: PS 307 / PS 305 series (24 VDC load supply required)
- Communication: Compatible with PROFIBUS DP and MPI configurations via CPU
Selection Guide
Use the criteria below to confirm the 6ES7321-1EH01-0AA0 is the right module for your application, or to identify the best alternative:
- Channel count needed ≥ 32 at 24 VDC? → 6ES7321-1EH01-0AA0 or -1EH02-0AA0 (successor)
- Channel count 16, 24 VDC, no diagnostics? → 6ES7321-1BH02-0AA0
- Channel count 16, 24 VDC, with diagnostic interrupt? → 6ES7321-1CH20-0AA0
- AC field signals (120/230 VAC)? → 6ES7321-1FF01-0AA0
- High-density I/O in compact rack? → Consider S7-300 compact CPUs with integrated DI
- Migration to S7-1500? → ET 200MP DI module 6ES7521-1BH00-0AB0 (requires TIA Portal re-engineering)
Quality Assurance & Sourcing
All modules supplied by Konmask.com undergo the following quality process:
- Visual inspection and label verification against SIEMENS factory markings
- Functional power-on test and channel continuity check
- Anti-static packaging with humidity indicator card
- Traceability documentation available on request (batch number, country of origin)
- Sourced from authorized distributors or verified surplus channels — no counterfeit risk
How to Order
- Part Number: 6ES7321-1EH01-0AA0
- MOQ: 1 piece
- Lead Time: In-stock items ship within 1–3 business days; sourced items 5–15 business days
- Payment: T/T, PayPal, credit card via Shopify Payments
- Shipping: DHL / FedEx / UPS worldwide; sea freight available for bulk orders
- RFQ for volume pricing: support@konmask.com
Replacement & Compatibility FAQ
Q: Is 6ES7321-1EH01-0AA0 discontinued?
A: SIEMENS has released the -1EH02-0AA0 as the current production revision. The -1EH01-0AA0 remains available as a spare part through authorized channels and verified surplus stock.
Q: Can I replace -1EH01-0AA0 with -1EH02-0AA0 without changing my STEP 7 project?
A: Yes. The -1EH02-0AA0 is a drop-in hardware replacement. You may need to update the GSD/hardware catalog in STEP 7 or TIA Portal, but no logic changes are required.
Q: Will this module work with an S7-400 rack?
A: No. The 6ES7321 series is exclusively designed for S7-300 backplane architecture and is not compatible with S7-400 racks.
Q: What is the difference between -1EH01 and -1EH02?
A: The -1EH02 is the revised hardware version with minor component updates for improved longevity; functional specifications are identical.
Q: Do you provide a warranty?
A: Yes. Konmask.com provides a 12-month warranty against manufacturing defects on all modules supplied. Contact support for claims.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
