Intel ZT 7102 Watchdog Timer, Battery Backup, Replacing the Battery, Battery Characteristics

Intel® NetStructureTMZT 7102 Chassis Management Module

Hardware Specifications

Enable RFC 868 Time Protocol on CMM (client):

1.Create file "/etc/rdate.cfg".

2.Edit file "/etc/rdate.cfg" with a valid host name or IP address of an enabled RFC 868 Time Protocol server.

3.Reboot the CMM, and check the new date (use "date") to make sure it is identical to the RFC 868 Time Protocol server (use "busybox rdate -p <host name or IP>".

4.This file will only be preserved during upgrades to same or newer versions.

Note: Since rdate is executed during CMM boot, it is possible that on a chassis powerup the CMM may not be able to sync up with a server if the network path to it is through the backplane Ethernet port. For proper network time synchronization during CMM boot, the CMM should be able to contact the time server through the front Ethernet port.

2.19Watchdog Timer

The ZT 7102 uses a Maxim* MAX6374KA-T watchdog timer to supervise processor activity. When the software fails to strobe the watchdog within a set period (once every second), the watchdog alerts the CMM's Complex Programmable Logic Device (CPLD), which resets the CPU.

2.20Battery Backup

The CMM contains a CR 1025 onboard battery to retain certain functions such as the real time clock, even when no standby power to the board is present. If it becomes apparent that the time and date no longer stay current, then the battery should be replaced. The battery should only be replaced with a lithium CR 1025 or equivalent. After the battery is replaced, use the setdate command to set the time correctly. See Section 2.17, “Real Time Clock” on page 34 for information on setting the time and date.

Note: Date and time are critical to the operation of the CMM because health events are stamped with this information. Always ensure the date and time of the CMM are kept current.

2.20.1Replacing the Battery

1.Slide the battery out from the battery retention clip.

2.Slide the new battery into the clip with the positive (+) side up. The metal arm of the retention clip should rest on top of the positive side of the battery.

Table 18. Battery Characteristics

Characteristic	Description
Battery Voltage:	3 V
Battery Capacity:	30 mAh
Real-Time Clock Requirements:	300 uA typical, 500 uA maximum (Vbat = 3 V, Vcc = 0 V)
Real-Time Clock Data Retention:	11.4 years typical/6.8 years minimum (not powered). When powered,
	RTC takes its power from +5v, not battery.
Electrochemical Construction:	Long-life lithium with solid-state polycarbon monofluoride cathode.

Technical Product Specification 35