How to add a Simplex NAC card to a Simplex 2001 FACP

I am connecting two new horn strobes to an existing Simplex 2001-8023 FACP. The existing NAC module is a #556-874F. There is no march time module in the panel. The existing horn strobes are the old 2903s which are obsolete. I was told by my Simplex salesman the new TruAlert 4906-9127 would work with this panel. I installed them and they do not work. I realized when I sounded the alarm, I later realized the existing horn strobes had a temporal alarm or a march time type sound.
I know from past experiences with other old panels, new devices today require a constant alarm voltage (24VDC). Can somebody tell me if the Simplex 556-874F signal module puts out a pulsating voltage? If it does, I need to add a separate circuit for the new horn strobes. Does anybody know the required Simplex NAC card model number which applies constant 24VDC alarm voltage? I would greatly appreciate any help. Thanks!

The 4906-9127 is a SmartSync TrueAlert and requires either a 4905-9938 SmartSync module or a Simplex panel that has SmartSync built into it (and the 2001 isn’t one of them).

Therefore, you will need a 4905-9938 module in order for the TrueAlerts to work.

However, I would advise you to be careful as that there’s a chance that the 2001 could put out FWR due to one of the capacitors draining out as that FWR isn’t tolerable not just to TrueAlert NAs, but also the SmartSync module.

Firealarmveteran15 has it correct. The 4906-9127 is a SmartSync device and will not work without a SmartSync NAC or control module. However, SG does have non SmartSync devices available, but they may have to be ordered.

The 2001-8023 does use unfiltered power (FWR) for the NACs. This can shorten the life of the modern devices. A 4905-9938 SmartSync control module may not work at all on FWR power.

The 556-874 does not have any internal circuitry to pulse the voltage to the signals. A march time module, code 3 module, coder module, or some DIY device hidden in the panel is required to supply pulses to the 556-874. The other alternative is that the existing notification appliances are being coded by a device external to the FACP.