User's Manual

Page 26

E Series Data Radio – User Manual

Part E – Getting Started - ER450

User Interfaces – Ports A & B

Each user port (A & B) is wired as a RS232 DCE, conﬁgurable for

no handshaking (3-wire) interface, or for hardware or software (X-

on/X-off) ﬂow control. In most systems ﬂow control is not required,

in which case only 3 wires need to be connected between the radio

and the application device.

Typical pins used:

• Pin 2 (RxD) - data output from the radio modem,

• Pin 3 (TxD) - data input to the radio modem,

• Pin 5 (SG) - signal ground.

See Part D – System Planning and Design - Data Connectivity, for

further details of other cable conﬁgurations.

RS232 Connector Pin outs (DCE)

Port A and B, Female DB9

Activating the Transmitter

In most systems, the transmitter by default is controlled

automatically by the radio when it has data to transmit.

In some systems, such as full duplex point-to-point links or full

duplex point-to-multipoint base stations, it is desirable to run the

transmitter all the time (hot keyed).

Two mechanisms are provided to do this:

• the radio modem can be conﬁgured to transmit continuously

whenever powered, or

• the radio modem can be conﬁgured to transmit whenever an

external RTS signal (Pin 7) is applied to one (or either) user

ports. (To simulate an external RTS input, loop pins 6 to 7).

To operate in these modes, the radio must be conﬁgured via the

programming software.

Caution: When the radio is conﬁgured to transmit

continuously, ensure an RF load is present BEFORE

applying power to the unit.