Integrated speed sensor and safety controller

The Allen-Bradley Guardmaster MSR57P speed monitoring safety relay effectively combines the functionality of a speed sensing module with a configurable safety controller. The MSR57P is suitable for safety applications where access is required to guarded areas, under defined and controlled conditions, while a machine is still running.

Able to monitor up to two encoders and five dual-channel safety sensors, the MSR57P supports a wide range of safety modes and is suited to safety applications up to SIL3 and Cat4. The unit is able to concurrently monitor motion, E-stop devices, guards, enabling switches and selection switches, and further permits monitoring of single- and multi-axis machines with one dedicated MSR57P per axis. It also supports six safety outputs and four auxiliary outputs.

The MSR57P has the functionality to monitor safe maximum speed (SMS), safe limited speed (SLS), standstill speed, safe direction of rotation and safe acceleration rate. The MSR57P can utilise SLS monitoring to determine if it is safe to access a machine area when the machine is still running.

The MSR57P also supports inputs from a three-position enabling switch. The enabling switch can be held by an operator entering the hazardous area. As long as a constant pressure is applied, the enabling switch - connected via an umbilical cable to the MSR57P - permits the machine to continue running below the SLS. If, however, the switch is either released or squeezed too hard - as would be the case if the operator risked injury - the machine would be immediately de-energised.