Honeywell HC900 User Manual

Operating Characteristics - Power Down / Power Up
146 HC900 Process Controller Installation and User Guide Revision 19
06/14
Figure 79 – Warm Start Operation
Cold Start
A Cold Start clears the data in battery backed RAM, turns all outputs off, transfers the configuration file
from flash memory to RAM and reinitializes all dynamic data.
The Cold Start procedure is flowcharted in Figure 80. The controller initiates the Cold Start procedure:
• After a power outage, when diagnostics indicate that the controller hardware and software program are
intact, but the content of the RAM database is incorrect. (See Figure 79.)
• On a Mode transition from PROGRAM to RUN. (This Mode transition can be initiated by operating the
Mode switch on the controller or RSM, or by exiting the Program mode at an operator interface.)
• When initiated by the user (after download with Cold Start selected, or any transition from PROGAM
Mode to RUN Mode.)

Honeywell HC900 Specifications

General

Series	HC900
Redundancy	Optional
Programming Language	Function Block Diagram, Ladder Logic, Structured Text
Inputs	Analog, Digital
Outputs	Analog, Digital, Relay
Display	Optional
Control	PID, Advanced Control
Power Supply	24V DC or 100-240V AC
Storage Temperature	-40°C to 85°C
Humidity	5% to 95% non-condensing
Communication Protocols	Modbus, Ethernet