Siemens Fail-Safe IO Module

Oct 29

3 min read

Digital Input/Output Modules

The fail-safe modules of Siemens SIMATIC S7-1200 G2 Controller permit the implementation of safety-related application requirements integrated into the overall automation. The safety functions required for fail-safe operation are integrated in the modules. Communication with the fail-safe SIMATIC S7-1200 G2 CPUs is performed by means of PROFIsafe mechanisms. The module can only be operated in central configurations.

Digital inputs and outputs as supplement to the integrated I/O of the fail-safe CPUs
Integrated into the overall automation for implementation of safety-related requirements
With integrated safety functions
Communication with fail-safe CPUs via PROFIsafe mechanisms
For flexible adaptation of the controller to the corresponding task
For subsequent expansion of the system with additional inputs
Operable exclusively in the central system

Digital Inputs

Number of digital inputs: 6; 4 fail-safe inputs: 2 (1oo2), 4 (1oo1), or a mix; 2 standard inputs

in groups of: 6

Sourcing/sinking input: No

Input characteristic curve in accordance with IEC 61131, type 1: Yes; Current-sinking

Input voltage

Rated value (DC): 24 V
for signal "0": -3 to +5V
for signal "1": +15 to +30V

Input Current

for signal "0", max. (permissible quiescent current): 0.5 mA
for signal "1", min.: 2.5 mA
for signal "1", typ.: 4 mA; 6 mA maximum

Input delay (for rated value of input voltage)

for standard inputs

-- parameterizable: Yes; Fail-safe: 0.8 / 1.6 / 3.2 / 6.4 / and 12.8 ms (selectable individually) Standard: 0.2 / 0.4 / 0.8 / 1.6 / 3.2 / 6.4 / and 12.8 ms (selectable together)

Cable length

shielded, max.: 500 m
unshielded, mas.: 300 m

Digital Outputs

Number of digital outputs: 2

in groups of: 2

Short-circuit protection: Yes; per channel, electronic

Response threshold, typ.: 10 A

Open-circuit detection: Yes; per channel, only detects when output is off with PM load that allows small negative current

Overload protection: Yes; per channel

Response threshold, typ.: 4 A; measured at P-switch for more than 0.5 s

Limitation of inductive shutdown voltage to: Typ. -74 V (typ. -26 V P-switch; typ. +48 V M-switch)

Controlling a digital input: Yes; Only permitted in PP mode, not with PM mode

Switching capacity of the outputs

on lamp load, max.: 10 W

Output voltage

Rated value (DC): 24 V
for signal "1", min.: 2L+ (-2.0 V); P-switch: 2L+ (-1.5 V); M-switch: 0.5 V

Output current

for signal "1" rated value: 2 A
for signal "1" permissible range, max.: 10 mA to 2 A; 4 A total for all outputs
for signal "0" residual current, max.: 0.5 mA; P-switch or M-switch

Parallel switching of two outputs

for uprating: No
for redundant control of a load: No

Switching frequency

with resistive load, max.: 30 Hz
with inductive load, max.: 0.1 Hz
on lamp load, max.: 10 Hz

Cable length

shielded, max.: 500 m
unshielded, max.: 30 m for hardware version FS-01; 10 m for hardware revision FS-01 when used in burner applications related to EN 298

Design

4 fail-safe inputs (SIL 2/Cat. 3/PL d) or 2 fail-safe inputs (SIL 3/Cat. 4/PL e)
- Suitable for switches and 3/4-wire signal transmitters according to IEC 61131, type 1
- Four short-circuit-proof encoder supplies, one per input
- External encoder supply possible
2 fail-safe digital outputs, PPM-switching (SIL 3/Cat. 4/PL e)
- Deactivation dark test (max. SIL 2/Cat.3/PL d)
- Configurable as PP or PM-switching
- 2 A output current per output
2 digital standard inputs
Integrated emergency stop function for up to 50% faster response time
Channel-wide and module-wide passivation
Module fault indicator (DIAG; red/green LED)
Status display for each input and output (red/green LED)
Plain text identification of module type and function class:
- Digital nameplate (ID-Link)
- Hardware and firmware version
- Complete Article No.

Power-Flo Technologies is proud to partner with Siemens SIMATIC S7-1200 G2 and their fail-safe modules that provide a flexible solution for integrating safety-related functions into automation systems. With fail-safe digital inputs and outputs, integrated safety functions, and PROFIsafe communication, these modules help meet a range of application requirements while supporting reliable machine operation. Features such as short-circuit and overload protection, configurable input and output options, and integrated emergency stop functionality further enhance system safety and flexibility. Designed for central configurations, these modules make it easier to adapt and expand automation system to meet evolving operational needs.