Tyco Safety Products / Software House PI26 Manuel D’Utilisation
Introduction
C-4
apC/8X Technical Manual
Figure C.1: Sample Diagram apC/8X and Readers
Calculating Wire Ranges for RM4 Readers
From Table C-1, the RM4 Reader draws 75 mA (rounded up to 100 mA or .1
A), as listed in
A), as listed in
From Table C-2, the resistance with 18 AWG wire is 0.00879 ohms per foot.
From Figure C.1, the diagram shows that you are going to connect three
RM4s to the apC/8X. The RM4/4Es are laid out as follows.
RM4s to the apC/8X. The RM4/4Es are laid out as follows.
RM A is 50 ft. from the apC/8X
RM B is 500 ft. from RM A.
RM C is 250 ft. from RM B.
RM B is 500 ft. from RM A.
RM C is 250 ft. from RM B.
Perform wire range calculations, as follows:
1. Calculate the voltage drop for each reader in the chain by multiplying
the distance between each device by power (amps) by resistance (ohms
per foot).
per foot).
2. Add the voltage drop for each reader to get the total voltage drop.
3. Subtract the total voltage drop from the original apC/8X supply.
4. Is remaining voltage sufficient to operate the readers?
apC
Panel
RM4/4E
Reader
A
RM4/4E
Reader
C
RM4/4E
Reader
B
50 ft.
500 ft.
250 ft.
RM Port
Terminate
12 VDC