Integration Guide

WIT2410

40kbps (Since the over the air transmission is synchronous, the 32kbps synchronous over

the air rate is equivalent to 40kbps asynchronous into the radio serial port). If the base

transmits continuously at a higher rate than this, unless the default settings are changed,

the transmit buffer will eventually overflow. To allow a higher base throughput, either

increase the base slot size or the hop duration or both. A similar analysis needs to be

performed for the remote radios. Refer to Section 2.2.3 TDMA Mode for the remote

throughput calculation.

4.4. Power-On Reset Requirements

The WIT2410 has an internal reset circuit that provides a reset signal to the

microprocessor if the supply voltage to the WIT2410 falls below 2.7 volts. Operation of

the microprocessor at voltages below this voltage is unspecified and can result in

corruption of the program memory. When the radio is first powered on, there is an inrush

current in excess of 250mA. The power supply in the host must be capable of sourcing

this current without the voltage falling below 2.7 volts at the radio. Failure of the power

supply to meet this requirement can result in “motorboating” of the radio where the

inrush current of the radio pulls the supply voltage below 2.7 volts causing the reset

circuit to fire which resets the radio removing the current requirement. Once the voltage

recovers to a level above 2.7 volts, the reset signal is removed from the radio which

causes the inrush current which causes the voltage to drop causing the reset circuit to fire

and so on.

If the host circuitry has a reset circuit that generates a reset signal to the radio anytime

the power supply voltage falls below 2.7 volts, the on-board reset circuit can be disabled.

Murata recommends leaving the reset circuit enabled unless it causes a problem due to a

soft turn-on of the power supply voltage by the host. Please contact Murata Technical

Support for details on disabling the reset circuit.