Glad you caught that one! For some reason I saw Security Alarm System's EOL Resistor when I read the original question <]:-)..
I have only done Security / Burglar Alarm systems, where the EOL Resistor and the zone's loop functions as I posted. Any Fire / Life / Safety systems for the Commercial Projects we do are sub'ed out to other ECs that are familiar with the existing systems [typically Simplex], so they get all the compatable strobes, etc. and programming according to that setup.
Is the EOL Resistor's function on F/L/S systems similar to the Security system's? - To have an X value of current flowing steadilly through the loop during normal operation [functioning NAND or NOR gates will be "Inverted" (NOT Logic or Logic 0) with EOL in circuit], or do the EOL Resistors become connected when the remote device trips [alarm], which would make the logic Gates AND, OR or possibly XOR?
Any info is helpful..
Originally posted by dandy467d:
Your reply is correct for security alarm systems, not for fire systems. Loss of the supervisory voltage due to cut wire, missing device, etc. will give you a zone trouble, not a alarm condition.