The PNOZsigma series from Pilz is a family of safety relays used for monitoring safety functions in machinery and automation systems. When it comes to two-hand monitoring, the PNOZsigma relays are commonly employed to ensure the safety of operators during manual operations. Two-hand monitoring is a safety measure designed to protect operators from hazardous machine movements. The basic idea is that the operator must use both hands to initiate a dangerous machine function. This ensures that both hands are away from the danger zone, reducing the risk of injury. PNOZsigma safety relays also monitor for faults such as wire breaks or short circuits in the input circuit. If a fault is detected, the relay will prevent the machine from starting to maintain a safe operating environment. PNOZsigma relays are designed to comply with safety standards, and the safety category depends on the specific model and configuration. Safety categories are designated by standards like EN ISO 13849 or IEC 62061. Once the two-hand operation is complete, there is usually a reset function to allow the operator to safely reset the system for the next cycle. http://www.pilz.com
PNOZsigma safety relays typically have dual input channels for connecting two hand-operated devices or buttons. These devices are usually positioned in a way that requires the operator to use both hands simultaneously. The safety relay uses internal logic to monitor the signals from the two hand-operated devices. The logic ensures that both inputs are activated within a specified time window and that they remain activated during the entire dangerous machine cycle. The relay includes time monitoring functions to ensure that the two inputs are activated within a defined time frame. If one of the inputs is not activated or if the timing is not correct, the safety relay will prevent the machine from starting or will initiate a safe shutdown. http://www.pilz.com