Pilz is introducing a new PSSu K F EI safe motion monitoring module for use with its PSSuniversal PLC and PSSuniversal multi controllers, both of which are part of the company's proven PSS 4000 programmable safety system family.
The new PSSu K F EI module monitors motion/speed and evaluates signals in a similar way to the Pilz PNOZ s30 standalone speed monitor, enabling fast local shutdowns when speeds or motions are detected to be outside the predetermined safe range (the limit values). A maximum of eight axes of motion can be monitored per control system.
Each PSSu K F EI module has an Mini-I/O socket for the encoder interface, plus there is an input for direct wiring of initiators. Local outputs on the module enable fast shutdowns when limit values are exceeded, and the safe motion monitoring modules can be cascaded for fast synchronous shutdowns; if one module in the network detects an error, all safe motion monitoring modules can trigger shutdowns within 1ms. By controlling the shutdowns locally, directly from the modules, shutdown times are independent of PLC cycle times.
Simple connection, multiple safety functions
Setting up the speed/motion monitoring is straightforward by means of the PAS4000 configurator. First, the connected encoder is configured, then the parameters for each function are set using the wizard - including whether or not a local shutdown is required. Function blocks enable the monitoring function threshold values to be set as necessary. In addition to the SSM (safe speed monitoring), SSR (safe speed range), SDI (safe direction) and SOS (safe operating stop) functions, an SS1 (safe stop) function can be implemented via the safe timer that is integral within the module.
Onboard intelligence enables the module to shutdown processes without recourse to the main controller, but data from the module is still available centrally. For example, the main controller (and programme) has access to speed values, hence functions such as synchronisation monitoring can be implemented.
Users have a choice of encoder or feedback system, including sin/cos, TTL and HTL. Safety functions can be implemented as follows, in accordance with the requirements of EN 61800-5-2 (Adjustable speed electrical power drive systems. Safety requirements. Functional ):
- up to PL d with only one sin/cos rotary encoder
- up to PL e with one safety-related rotary encoder
- up to PL e with a combination of rotary encoder and proximity switch, with additional gear monitoring
For connecting encoders to PSSu K F EI safe motion monitoring module, Pilz offers the PNOZ msi b4 Box; this has an input for the encoder, another for a power supply, and a third that connects the PNOZ msi b4 Box to the PSSu K F EI module. If necessary, the PNOZ msi b4 Box can loop-in the power supply for the encoder, making for a very neat installation. A Mini-I/O cable is also available for making the connection between the PNOZ msi b4 Box and the PSSu K F EI module, in lengths of 1.5m, 2.5m and 5m.