For applications requiring 10 or more safety contacts, Pilz is launching new expansion modules for use with its slimline PNOZsigma relays.
The PNOZ s7.1 features three normally-open safety contacts. It is connected, by means of a simple plug, to a PNOZsigma ‘base unit’ safety relay type PNOZ s1, s2, s3, s4, s5, s6 or s6.1. It also incorporates a separate feedback loop that enables the 17.5 mm wide module to be used as a standalone safety relay.
Further expansion is possible by connecting a maximum of 10 PNOZ s7.2 modules, each having four normally-open safety contacts and one normally-closed auxiliary contact. Alternatively, a PNOZ s7.2 can be connected to a base unit as a single expansion module. It also measures 17.5 mm wide.
For applications requiring an even greater number of contacts, multiple PNOZ s7.1 modules can be used, each with a maximum of 10 PNOZ s7.2 modules. The only additional requirement is that a 24 V supply must be provided for each PNOZ s7.1 module. Although there is theoretically no limit to the number of PNOZ s7.1 expansion modules that can be used, each one adds 20 ms to the 50 ms reaction time of the base unit. Care must therefore be taken to ensure the total reaction time remains acceptable.
Industries where the PNOZ s7.1 and PNOZ s7.2 modules are expected to prove particularly useful are automotive and paper. However, they are equally suitable for other industries where 10 contacts or more are required.
