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Siemens 6ES7321-1FH00-0AA0 — Digital Input Modules

Siemens 6ES7321-1FH00-0AA0 SM 321 Digital Input, 16 DI AC, 1

MPN6ES7321-1FH00-0AA0

End of Life

Siemens SIMATIC S7-300 SM 321 digital input module, 6ES7321-1FH00-0AA0, 16 digital inputs, 120/230 V AC isolated, 1x 20-pole, 40 mm wide.

$190.50 – $381.00Ref. price · indicative, final on quote

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Siemens 6ES7321-1FH00-0AA0 datasheet (PDF)

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

6ES7321-1FH00-0AA0 — Inputs
Parameter	Value
Number of digital inputs	16
Max. inputs, up to 40 °C	16
Max. inputs, up to 60 °C	16
2-wire sensor support	Yes

6ES7321-1FH00-0AA0 — Electrical
Parameter	Value
Input voltage at signal "1"	79 to 264V
Input voltage type (AC/DC)	AC
Input voltage at signal "0"	0 to 40V
Input current at signal "1" (typ.)	6.5 mA; (120 V, 60 Hz), 16 mA (230 V, 50 Hz)
Power loss (typ.)	4.9 W
Current consumption from backplane bus (5 V DC), max.	29 mA
Permissible quiescent current, 2-wire sensor, max.	2 mA
Cable length, unshielded, max.	600 m
Cable length, shielded, max.	1 000 m

6ES7321-1FH00-0AA0 — Timing
Parameter	Value
Input delay 0 to 1, min.	25 ms
Input delay 0 to 1, max.	25 ms
Input delay 1 to 0, max.	25 ms
Input delay, parameterizable values	No

6ES7321-1FH00-0AA0 — Diagnostics & Isolation
Parameter	Value
Diagnostics function	No
Diagnostic alarm	No
Hardware interrupt support	No
Isolation between channels	No
Isolation between channels and backplane bus	Yes; Optocoupler
Isolation test voltage	4 000 V DC
Channels per isolated group	4
Status indicator per channel (green)	Yes

6ES7321-1FH00-0AA0 — Mechanical
Parameter	Value
Depth	120 mm
Height	125 mm
Width	40 mm

6ES7321-1FH00-0AA0 — Specifications
Parameter	Value
Rated value (AC)	230 V; 120/230 V AC (47 ... 63 Hz)

Product details

This 6ES7321-1FH00-0AA0 is a SIMATIC S7-300 SM 321 digital input module – 16 isolated AC inputs rated for 120/230 V AC (47–63 Hz). It reads line-voltage signals from switches, proximity sensors, or pushbuttons directly, without an interposing relay. Each input group of four is optically isolated from the backplane bus.

20-pin front connector required (not included). Unshielded cable max. 600 m; shielded cable max. 1 000 m. Isolation tested at 4 000 V DC between channels and backplane.