Fail-safe digital output modules are used centrally with SIMATIC S7-31xF-2 DP, and in the ET 200M distributed I/O device together with SIMATIC IM 151-7 F-CPU, S7-31xF-2 DP, S7-416F-2 and S7-400F/FH.The modules are, for example, suitable for connecting solenoid valves, DC contactors and indicator lights.

In the case of the SM 326 F-DO 10 x DC 24V/2A PP (6ES7 326-2BF10-0AB0), the function “Keep last valid value” can be used optionally in safety mode too. Together with the diagnostics capability of the module, this can be used for cost-optimized implementation of applications in, for example, the area of fire and gas alarm systems (in accordance with EN 54-2/-4 or NFPA72).

Siemens Fail-safe Digital Output Modules SIMATIC S7-300 Product Specifications:

Article number	6ES7326-2BF10-0AB0	6ES7326-2BF41-0AB0
	SM326, F-DO10XDC24V/2A PP, failsafe	SM 326, F-DO 8 X DC 24V/2A PM
Supply voltage
Rated value (DC)	24 V; 1L+	24 V; 1L+
Reverse polarity protection	Yes	Yes
Load voltage L+
● Rated value (DC)	24 V; 2L+, 3L+	24 V; 2L+, 3L+
● Reverse polarity protection	No	No
Input current
from supply voltage 1L+, max.	100 mA	75 mA
from load voltage 2L+ (without load), max.	100 mA	100 mA
from load voltage 3L+ (without load), max.	100 mA	100 mA
from backplane bus 5 V DC, max.	100 mA	100 mA
Power loss
Power loss, typ.	6 W	12 W
Digital outputs
Number of digital outputs	10	8
Short-circuit protection	Yes	Yes
Limitation of inductive shutdown voltage to		L+ (-33 V)
Switching capacity of the outputs
● on lamp load, max.	5 W	5 W
Output voltage
● for signal “1”, min.	L+ (-1.0 V)	L+ (-1.0 V)
Output current
● for signal “1” rated value	2 A	2 A
● for signal “1” permissible range for 0 to 40 °C, min.	7 mA	7 mA
● for signal “1” permissible range for 0 to 40 °C, max.	2.4 A	2 A; 2 A for horizontal installation, 1 A for vertical installation
● for signal “1” permissible range for 40 to 60 °C, min.	7 mA	7 mA
● for signal “1” permissible range for 40 to 60 °C, max.	2.4 A	1 A; for horizontal installation
● for signal “0” residual current, max.	0.5 mA	0.5 mA
Switching frequency
● with resistive load, max.	25 Hz	30 Hz
● with inductive load, max.	25 Hz	2 Hz
● on lamp load, max.	10 Hz	10 Hz
Total current of the outputs (per group)
horizontal installation
— up to 40 °C, max.	10 A	7.5 A
— up to 60 °C, max.	6 A	5 A
vertical installation
— up to 40 °C, max.	5 A	5 A
Cable length
● shielded, max.	1 000 m	200 m; 200 m for SIL 3, AK 6, Cat 4
● unshielded, max.	600 m	200 m
Interrupts/diagnostics/status information
Alarms
● Diagnostic alarm	Yes	Yes; Parameterizable
Diagnoses
● Diagnostic information readable	Yes	Yes
Diagnostics indication LED
● Fail-safe operation	Yes	Yes
● Group error SF (red)	Yes	Yes
Potential separation
Potential separation digital outputs
● between the channels	Yes	Yes
● between the channels, in groups of	5	4
● between the channels and backplane bus	Yes	Yes
● between the channels and the power supply of the electronics	Yes	Yes
Isolation
Isolation tested with	370V for 1 min	500 V DC/350 V AC
Standards, approvals, certificates
Highest safety class achievable in safety mode
● acc. to DIN VDE 0801	AK 5 and 6
● acc. to EN 954	Cat. 4	Cat. 4
● Performance level according to ISO 13849-1	e	e
● SIL acc. to IEC 61508	SIL 3	SIL 3
connection method / header
required front connector	40-pin	40-pin
Dimensions
Width	40 mm	80 mm
Height	125 mm	125 mm
Depth	120 mm	120 mm
Weights
Weight, approx.	330 g	465 g