Abstract: A safety I/O module includes a plurality of output channels and a plurality of channel output terminals. The safety module further includes a multi-channel high side switch comprising an integrated circuit including a voltage input terminal and a plurality of main switches. A plurality of discrete safety switches are also provided. Each of the output channels includes a redundant pair of switches including one of the main switches of the multi-channel high side switch and one of the safety switches arranged in series. The main switch and the safety switch are configured to: (i) operably connect the voltage input terminal of the multi-channel high side switch to a respective one of the channel output terminals when both the main switch and the safety switch are in a conductive state; and (ii) disconnect the voltage input terminal of the multi-channel high side switch from the respective one of the channel output terminals when at least one of the main switch and the safety switch are in a non-conductive state.

Abstract: An electrical relay system is configured to allow for failure detection of a relay by injecting a signal at a common contact of the relay and looking for the signal at a normally closed contact of the relay. If the relay is commanded to be “off,” or closed, and the injected signal is not detected through the normally closed contact of the relay, then the system can determine that a failure condition has occurred. In one aspect, the system can include multiple relays with the signal being injected at a common node of the relays. In another aspect, the system can include multiple controllers for controlling and/or monitoring the electrical relay system. The electrical relay system can be coupled to screw terminals for connecting to a field device as part of an industrial automation system.

Abstract: An electrical relay system is configured to allow for failure detection of a relay by injecting a signal at a common contact of the relay and looking for the signal at a normally closed contact of the relay. If the relay is commanded to be “off,” or closed, and the injected signal is not detected through the normally closed contact of the relay, then the system can determine that a failure condition has occurred. In one aspect, the system can include multiple relays with the signal being injected at a common node of the relays. In another aspect, the system can include multiple controllers for controlling and/or monitoring the electrical relay system. The electrical relay system can be coupled to screw terminals for connecting to a field device as part of an industrial automation system.

Abstract: An I/O circuit for measuring temperatures within an industrial control system uses a stored empirical model together with input from at least one reference temperature sensor to determine inter-terminal temperature differences for more accurate cold junction compensation.