Rockwell Automation has released its new intelligent Allen-Bradley Guardmaster MSR57P speed monitoring safety relay. The first of its kind on the market, this unit provides a complete solution to monitor all motion for small to mid-size machines, and provide appropriate safety control. This effectively combines the functionality of a speed sensing module with a configurable safety controller. The MSR57P is ideal 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. While the machine is running above the SLS, access to the area will be denied. Once the machine is running below the pre-determined SLS, however, the MSR57P can monitor and control a solenoid gate switch to permit access to the area.
Moreover, the MSR57P supports inputs from a three-position enabling switch, as an additional aid to operator safety. 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 the switch is either released or squeezed too hard, however—as would be the case if the operator risked injury—the machine would be immediately de-energised.
The MSR57P will prove particularly useful in the web-process industry—including steel coil, paper, plastic, printing and film manufacturing applications—where there is an ongoing requirement to gain access while a machine is moving for thread-up, adjustment or other purposes.