On the FPD-7024, D7024, DS9400, DS9400I, DS9400M panels program a relay to follow output 54 (Ground Start).
*Note - PBX lines and ground start phone lines do not comply with NFPA requirements for digital communication.
Part numbers FPD-7024, D7024, DS9400, DS9400I, DS9400M, DS9465I, MX465, D7035, D7053