Allen-Bradley 1756 Series, User Manual, Page: 46 / 136

46 Rockwell Automation Publication 1756-UM013B-EN-P - October 2019
Chapter 3 1756-IB16S Input Module Features
The following apply to the test outputs:
• Test outputs can be configured as:
– Not Used
– Power Supply
– Pulse Test
• Separate test outputs are provided for short circuit detection of a safety
input (or inputs).
• Can supply 24V DC power to devices, such as safety sensors.
• Test output rating (TO) 200 mA @ 18…32V DC
Safety Application
Suitability Level
Table 6 describes the safety application suitability levels for the 1756-IB16S
module.
Table 6 - Safety Application Suitability for 1756-IB16S
Suitability Level Conditions Notes
Safety applications that are rated up to
and including
SIL CL3, PLd, Cat. 2 as
defined in IEC 61508, IEC 61511,
IEC 62061, and ISO 13849-1
The safety function uses single-channel mode.
• Module channel Point Mode is Safety Pulse
Test.
Consider the following:
• Single-channel mode and dual-channel mode, as stated in this table, refer to
the number of channels used in the safety function.
• The 1756-IB16S module is capable of being a SIL CL3/PLe/Cat. 4 subsystem
(SRP/CS) when either a single-channel or dual-channel safety device is wired
to the input channels.
• The channel mode type, that is, single or dual, affects Performance Level and
Category. You can use the modules in SIL CL3 applications regardless of channel
mode type.
The determining factor to whether a 1756 ControlLogix® I/O safety module
resides in a SIL CL3, PLe, Cat. 4 safety application is that the overall safety
architecture be a dual-channel system.
• To achieve SIL CL3 single-channel, the sensor that is used must be SIL CL 3
single-channel as well.
• The requirement that Point Mode be Safety Pulse Test assumes that only the
safety modules provide diagnostics to a specific Suitability Level.
The larger safety system within which the safety modules reside can provide
the diagnostics necessary to achieve the stated Suitability Level without the
requirement that Point Mode be Safety Pulse Test.
Safety applications that are rated up to
and including
SIL CL3, PLd, Cat. 3 as
defined in IEC 61508, IEC 61511,
IEC 62061, and ISO 13849-1
The safety function uses dual-channel
mode
(1)
.
• Module channel Point mode is Safety.
Safety applications that are rated up to,
and including,
SIL CL3, PLe, Cat. 4 as
defined in IEC 61508, IEC 61511,
IEC 62061, and ISO 13849-1.
The safety function uses dual-channel mode.
• Module channel Point Mode is Safety Pulse
Test.
The safety function uses dual-channel mode.
• Module channel Point mode is Safety.
• Use shredded cable or cable trunk to separate
channel wiring to mitigate short circuit
faults.
(1) You cannot configure the module for dual-channel operation via the Logix Designer application module properties dialog box. You use dual-channel safety instructions in the Safety Task to provide
cross monitoring.