RIM 902M, Integrator Manual

Page: 47 / 64

Interface specification: Pin descriptions 39
RIM 902M OEM Radio Modem – Integrator’s Guide
Pin 12 TRI Transmit Indicate
The active (radio transmitting) state of this line is high.
This output from the radio that is asserted while the RIM 900 is transmitting a
packet to the network base station. TRI can be used to provide real-time visual
feedback to the user that the radio is transmitting packets. If this is not
necessary, the line can simply be left disconnected.
This line is low when the Radio is off.
Pin 14 ~RI ~Ring Indicate
This is an output from the radio.
When ~DTR is not asserted (high), the RIM 900 asserts ~RI (low) to indicate
that it has data waiting for the computing device. The radio will not transfer the
data until ~DTR is asserted (low). This line can be used to wake up a
suspended computing device when the radio needs to communicate with it. If
~DTR is already asserted (low) when the radio has data to send the computing
device, ~RI will not be asserted.
For MASC implementations in normal serial mode, this line indicates that the
radio has any MASC frame to transfer to the computing device. For MASC
implementations in interactive serial mode, this line indicates that the radio has
received an MPAK from the Mobitex network, and has a MASC M frame
containing the MPAK to transfer to the computing device.
For RAP implementations, ~RI is not used and should not be connected. This
line should also be disconnected if your application does not use it.
Pin 15 ~CTS ~Clear To Send
This line is an output from the radio modem. The active (clear to send) state of
this line is low.
All MASC implementations require this line. This line is optional for RAP
implementations. To use hardware flow control with RAP, the radio must be in
interactive serial mode (see pin 10). Do not connect ~CTS if your application
does not require it.