Tested a configuration for h1pemmx in which the timing for the I/O chassis was connected directly to the master fanout with a single-mode fiber, and the IRIG-B card removed from the front-end computer. This would have allowed us to not use a timing fanout and IRIG-B fanout at the mid station for a single computer. This test failed, running the front-end computer with no IRIG-B card installed caused the IOP model to have a 0x4000 status (timing error) and the state word also indicated a timing error. I reinstalled the IRIG-B card in the computer, and restored the timing system connections to their original state. Single-mode fiber to the timing fanout at MX, multi-mode fiber connect the I/O chassis and the IRIG-B fanout, and coax cable connecting the IRIG-B fanout to the IRIG-B card in the front-end computer. Had difficulty getting the IRIG-B card to read the correct time, eventually moved the connection to the middle card in the fanout where it sync'd up without problem.