S600 Instruction Manual
The startup in-rush current may draw 6 Amps for approximately 100
milliseconds. This in-rush becomes significant when multiple flow
computers are connected to the same power supply.
An on-board anti-surge fuse (2.5 Amp rating) protects the supply line
should a fault occur within the unit.
Fully regulated 15 and 24 Volts dc supplies are also available for
applications such as powering loops or pre-amplifiers. These outputs
are protected by resettable thermal fuses.
Table 3-1. TB-1 Pin Connections (Power)
Pin Function
1
+24 V dc INPUT
2
0 V (Return) INPUT
3
+24 V dc OUTPUT (500 mA)
4
+15 V dc OUTPUT (100 mA)
5
0 V (Return) OUTPUT
3.2.1 Watchdog Relay
A single pole, double-throw relay with Normally Open or Normally
Closed terminals provides the watchdog status from pins 6, 7, and 8 of
TB-1. The TB-1 pin connections are shown in Table 3-2. Connection is
through plug-in, standard 5 mm pitch screw terminals.
The relay is energized during normal operation. A CPU failure causes
the relay to de-energize. The watchdog period is 2.5 seconds
maximum.
Note
:
Contact is rated at 1 Amp, 30 Volts dc and 30 Volts ac, and is a
Form “C” contact.
Table 3-2. TB-1 Pin Connections (Watchdog Relay)
Pin Function
6 Normally
Closed
7 Common
8 Normally
Open
3.2.2 On-Board Battery Backup
The battery backup is used to retain the contents of the SRAM on the
P152 CPU, the PC compatible BIOS CMOS memory area, and the
calendar clock. The battery is a board-mounted, nickel-metal hydride
cell. The standard battery is a Ni-MH rechargeable 3.6 volt, 140
mAmp/hour unit. Table 3-3 provides battery specifications.
To ensure that the battery is fully functional, the S600 software
routinely performs a regular load test on the unit.
Note
:
A voltage-sensing circuit monitors the status of this battery, and
raises an alarm if the battery voltage drops below the predefined limit.
Should this condition arise, please contact your local service centre or
factory for further assistance.
3-4 CPU
Revised
Jan-07
