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Radio Communications
The XFC6200EX was designed such that the customer would provide
local power and communications if required. However, in those cases
where power is not available and solar power is required, the Model
6270 Optional Equipment Unit can be used. The 6270 enclosure has a
charger/regulator module designed for solar input power and is typically
fitted with a solar panel and a 26 amp-hour battery. This is ample to
power the 6200EX flow computer and maintain some amount of
autonomy.
In situations where radio communication is required, the power
requirements of some radios might compromise the autonomy of the
system. This problem can be handled in the following ways:
1. Upgrade to the larger Model 6770 Optional Equipment Unit which
can handle a 42 amp-hour battery or two 26 amp-hour batteries.
2. Use low power radios such as the FreeWave® Spread Spectrum
radio.
3. Use radios that have a Sleep feature which lets the radio go to sleep
via a control line going low and then wakes up when the control line
is driven high or allowed to float. Totalflow has a Power Scheduler
application that runs in the 6200EX and switches an output called
COM1SW on COMM 1 and COM2SW on COMM 2. This is a FET
output which when in the OFF condition provides a path to ground
and when turned ON appears as an open. This may sound
backwards, but was designed this way to support radios with the
Sleep function.
4. Switch the radio's power off when not in use. Since the COM1SW
and COM2SW signal does not provide a switched voltage, the user
will need to provide an interposing relay to switch the radio's power
on and off. In order to do this, the enclosure is required to be in a
General Purpose area since adding the relay compromises the
enclosure's Division 2 certification. Below is a simplified drawing of
how this would work. Due to the polarity of the COMSWs, the radio
will need to be connected to a normally closed set of contacts.
XFC6200EX
14
COM1SW
Figure 11 (Using Interposing Relay)
6270 Enclosure
Relay
+ 12V
+ 12V
To Radio
Power Input
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