Maxium Loop Resistance per loop is 25 Ohms.
More Information about the Polling Loop:
Detection devices in the analog system receive power and communicate with the control panel over a two-wire circuit. This digital communications format resists interference from most types of EMI and RF generated noise. Use shielded cable for all detection circuits. Terminate the shield to the earth ground terminal on the D10024 Control Module. Mineral insulated copper cable (MICC) provides superior screening. Ground the drain wire to the earth ground terminal on the D10024 Control Module.
Bosch Security Systems, Inc. recommends shielded single pair twisted cable wiring with a drain wire such as Atlas #218 or West Penn Wire/CDT #D293. West Penn Wire/CDT #D293 has a nominal capacitance of 28 pF/ft between conductors.
Polling circuits may be wired as Class A or Class B circuits. Bosch Security Systems, Inc. recommends Class A configuration with the wiring returning to the D9067 Polling Circuit Module. This allows the module to poll the circuit in both directions, ensuring circuit operation in the event of a single break in the wiring and allowing the panel to identify the location of the break.
Polling Circuit Length Wire Gauge Up to 4,000 ft (1,219 m) 18 AWG (1.2 mm), 4,000 ft to 7,000 ft (1,219 m to 2,134 m) 16 AWG (1.5 mm)