Designed with a compact enclosure, the Silent Knight 5128 and 5129 four-channel, dual-line digital communicators are secondary communicators designed to monitor UL listed Siemens fire-alarm control panels. Designed and listed to be mounted in the System 3, SXL-EX and MXL system enclosures, Model 5128 provides four (4) fully supervised input channels, dual phone line interface with line-fault monitoring, automatic 24-hour self-test, and reports in eight standard communication formats. Programming and troubleshooting time are minimized by user friendly English language messages available with the Model 5230 local programmer and PC based remote downloading software, Model 5561. Product is UL864 Listed and meets NFPA 72 Chapter 4, for Central Station / Remote Station Monitoring, and UL Listed as a secondary communicator for connect to Siemens conventional and the MXL-series of fire alarm control panels.