The. Mosaic. Safety controllers can monitor several safety sensors and commands, such as safety light curtains, laser scanners, photocells, mechanical switches, mats, emergency stops, two-hand controls, concentrating management of these in a single, flexible device.

Mosaic system safety level up to: SIL 3 – SILCL 3 – PL e – Cat. 4
The Mosaic system integrate.

SAFETY INPUTS We can categorize different types of input:

• Digital inputs
• Inputs for Restart / EDM feedback
• Inputs for proximity switches and incremental encoder
• Analogical input

SAFETY OUTPUTS

• OSSD (static semiconductor safety outputs) dual channel
• OSSD (static semiconductor safety outputs) single channel
• High Current Safety Outputs single channel (2A max per channel)

TEST OUTPUTS Test output signals are used to monitor overloads and short circuits on input lines

STATUS OUTPUTS The status output signal is a programmable SIL1 / PL c output that can indicate the status of: an input. an output or a node of the logic diagram

SAFETY RELAY Safety relays with guided contacts. Safety relay provides two N.O. contacts and one N.C. contact in addition to the N.C. feedback contact

In this article, we would like to focus on the status outputs that can achieve SIL1 PL c safety level

STATUS OUTPUTS (SIL 1/PL c)

The Status are programmable SIL1 / PL c outputs 24 VDC (PNP active high – 100 mA max.) that can indicate the status of:

• An input
• An output
• A node of the logic diagram designed using the MSD Mosaic Safety Designer

Are available on the following MOSAIC modules: M1, M1S, M1S COM, MI8O2, MI8O4, MO2, MO4, MO4L, MOR4, MOR4S8, MO4LHCS8, MOS8, MOS16.

These status outputs have recently been certified SIL1, SILCL 1, PL c. They can therefore be used in all those applications where, for safety functions, a Performance Level (PLr) equal to “c” is required. For example, most Type C standards, applied to woodworking machines & plants, require a PL c as a safety level.

Standard UNI EN ISO 19085-1:2017

Let’s briefly analyze the standard: UNI EN ISO 19085-1: 2017 – Woodworking machines – Safety – Part 1: Common requirements. This standard gives the safety requirements and measures to reduce risks related to woodworking machines arising during operation, adjustment, maintenance, transport, assembly, dismantling, disabling and scrapping and which are common to machines used in the woodworking industry. The standard indicates a series of machine functions where a PLr equal to “c” is required. This means that the SRP/CS (Safety Related Parts of Control Systems), the part of machine control system able to maintain or achieve machine safety status in relation to the status of certain safety-related sensors must achieved the Performance Level “c” (PLr = c).

Following the list of some features that require this PLr:

• Start/Restart – Unexpected start/restart shall be prevented
• Normal stop – The machine shall be fitted with a control stop which, when activated, bring all machine actuators and any demountable power feed unit safely to a stop.
• Operational stops – The stand-still condition of the machina shall be monitored also after the machine stops.
• Emergency stop
• Braking function of tool spindle
• Mode selection – If it is necessary to operate the machine with reduced safety measures, e.g. for setting or adjustment, the machine shall be fitted with a mode selector.
• Spindle speed changing

USE

The diagram below shows, as an example, the connection of the two status outputs presents in the M1 module. These outputs drive two contactors K1 and K2. Given the low safety level (PL c), a high DCavg (diagnostic coverage) is not required. Therefore, the use of the feedback, to check the correct operation of the relay’s contacts, is not foreseen.

The status outputs are PNP type (active high) maximum of 100 mA current supplied. These outputs are suitable for driving components with current absorption lower than 100 mA.

Compatibility

The PL c safety level status outputs are available for all the models listed in the following table starting from December 2019. The table shows also the number of status outputs of each module.

For more information,
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