Codan Radio MT-4E Paging - Manual (Page 48)

USER GUIDE | MT-4E PAGING SYSTEMS
Chapter 5: Technical Information Page 40
UPGRADING FIRMWARE VERSIONS
Codan Radio Communications allows customers to upgrade the fi rmware of their MT-4E Receivers and
Transmitters via the Firmware Flashing Software and Firmware Upgrade fi les, available at the Codan
website www.danelec.com under Products - Software Downloads.
A type A to 5 pin mini-type B USB cable is used to connect the USB port of an IBM compatible computer
to the USB port on the front panel of the Receiver or Transmitter module.
It is not necessary to upgrade the fi rmware if the equipment is installed and is operating satisfactory. A
fi rmware upgrade is typically only needed to fi x minor software bugs or to upgrade the functionality of
the equipment.
Firmware versions earlier than 1.6.0 must be returned to the factory for upgrading. Contact the Codan
service department for more information.
PAGING TRANSMITTER BLOCK DIAGRAM
Figure 5-1 shows a block diagram of an MT-4E digital or analog paging transmitter using a CI-PM-3
Paging Modulator Card.
The paging encoder can be connected to the CI-PM-3 through auxiliary connections on the subrack /
motherboard or through a front panel DB-15 located on the front panel of the paging modulator card.
The analog / digital select control line of the paging encoder is fed to the transmitter and is used to
control the signal path in the transmitter.
Analog audio is fed directly through the paging card to the balanced audio input of the transmitter.
The incoming paging data from the paging encoder is connected to the appropriate 2 or 4 level input.
These signals are fed to control circuits that will turn on or off the appropriate pre-set control voltages,
which are then routed to the modulation input of a high stability reference oscillator (OCXO). The
modulated 10 MHz signal is fed to the reference input of the transmitter’s synthesizer. A component
of the digital page is also sent to the modulation input of the transmitter synthesizer through the direct
modulation input of the transmitter.
If the system requires a great amount of frequency stability, as required in simulcast transmissions, an
external high stability reference can be connected to the external reference input of the paging card.
The reference signal in combination with the paging cards phase lock loop (PLL) circuit will condition
the OCXO to +/-0.002ppm.