6ES7421-1FH20-0AA0 SIMATIC S7-400 Digital Input SM 421

6ES7421-1FH20-0AA0 SIMATIC S7-400 Digital Input SM 421

Key Technical Specifications

• Brand & Model: Siemens SIMATIC S7-400, 6ES7421-1FH20-0AA0 (SM 421).
• Inputs: 16 digital inputs, isolated per channel.
• Input Voltage: Rated UC 230 V (120/230 V AC/DC, 47-63 Hz).
• Signal "0" Range: 0 to 40 V AC / -40 to +40 V DC.
• Signal "1" Range: 74 to 264 V AC; 80 to 264 V DC, -80 to -264 V DC.
• Input Current (Signal "1"): Typ. 10 mA at 120 V AC, 14 mA at 230 V AC.
• Quiescent Current (Signal "0"): Max. 6 mA AC, 2 mA DC.
• Input Delay: 20 ms (0→1 AC), 15 ms (0→1 DC); 30 ms (1→0 AC), 25 ms (1→0 DC).
• Power Loss: Typ. 12 W.
• Backplane Bus Current: Max. 80 mA at 5 V DC.
• Cable Length: Shielded up to 1000 m, unshielded up to 600 m.
• 2-Wire Sensor Support: Yes, max quiescent current 5 mA.
• Diagnostics: No diagnostic function, but status LEDs per channel (green).
• Isolation: Between channels (groups of 4) and backplane bus. Tested at 1500 V AC.

Installation & Wiring Guidelines

• Mount the 6ES7421-1FH20-0AA0 module on a standard S7-400 rack.
• Connect the backplane bus via the 5 V DC supply (max 80 mA).
• Wire inputs using shielded cables for runs up to 1000 m.
• Use unshielded cables only for distances up to 600 m.
• Observe the polarity for DC signals and phase for AC signals.
• Group isolation: each group of 4 channels is isolated from others.
• Ensure the input voltage stays within the specified "0" and "1" ranges.

Package Contents

• One SIMATIC S7-400 6ES7421-1FH20-0AA0 digital input module.
• Front connector (screw-type, included).
• Labeling strips and coding elements.
• User manual (digital download).

Shipping & Logistics

• Shipping carriers: FedEx, UPS, DHL.
• We ship within 5 business days after order confirmation.
• All items are brand new and original Siemens products.
• We maintain stock for fast dispatch.
• 30-day return policy applies (terms and conditions).

Frequently Asked Questions (FAQ)

• Q: Is this module compatible with 230 V AC inputs?
  A: Yes, the 6ES7421-1FH20-0AA0 accepts 120/230 V UC (AC/DC).
• Q: Can I use 2-wire proximity sensors?
  A: Yes, it supports 2-wire sensors with max 5 mA quiescent current (AC).
• Q: What is the input delay for DC signals?
  A: For DC, 0→1 delay is 15 ms, and 1→0 delay is 25 ms.
• Q: Are all channels isolated from each other?
  A: Isolation is in groups of 4 channels; groups are isolated.
• Q: Do you have these in stock?
  A: Yes, we have 6ES7421-1FH20-0AA0 modules in stock ready to ship.
• Q: What shipping methods do you offer?
  A: We ship via FedEx, UPS, and DHL worldwide.

Contact Information: For inquiries, please email sales@nex-auto.com or call +86 153 9242 9628 (WhatsApp).

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