Emerson FLOBOSS S600 Instruction Manual page 23

FloBoss S600 Instruction Manual
The FloBoss S600 should be powered by a nominal 24 volts dc power source capable of supplying 2
Amps. The unit will operate between 20 and 32 volts dc.
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.
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 made by 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.
Contact is rated at 1 Amp, 30 volts dc and 30 volts ac, and is a Form "C" contact.
NOTE:
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.
This is a factory-fitted option. To ensure that the battery is fully functional, a regular load test is performed
on the unit.
NOTE: The status of this battery is monitored by a voltage sensing circuit. An alarm is raised if the
battery voltage drops below the predefined limit.
Rev Sep/04
Table 3-1. TB-1 Pin Connections (Power)
Pin
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
Table 3-2. TB-1 Pin Connections (Watchdog Relay)
Pin
6
7
8
CPU
Function
Function
Normally Closed
Common
Normally Open
3-3