B-73

Table B.4

Serial Connector, P2, signal names and functions

Signal electrical characteristics are given in the following table. T hese specifications comply with ANSI/EIA/TIA 232-E.

Table B.5

Serial signal electrical characteristics

Signal Name DB-9 P2 pin Sourced by Signal Function

-DCD 1 1 ctrl “carrier detect”, hands h ak e = ’0 ’ w h en co nt roller power
on
-DSR 6 2 ctrl “data set ready”, handshake=’0’ when controller power
on
RXD 2 3 ctrl serial data from controller to host
-RTS 7 4 host “ready to send”, handshake=’0’ when controller may
send
TXD 3 5 host serial data from host to controller
-CTS 8 6 ctrl used as “ready to receive”, handshake=’0’ when host
may send
-DTR 4 7 host ignored
RI 9 8 n/u not used
SG 5 9 com signal ground
n/u n/c 10 n/u conne ctor key

Parameter Value Applicable Signals1

1. Signals defined in Table 1. Serial Connector, P2, signal names and functions

EIA-232 subsec.

Minimum ON state input voltage2
2. Measured with respect to cir cuit SG, Signal Ground.
+3 volts TxD, RTS, DTR 2.1.3
Minimum OFF state input voltage2-3 volts TxD, RTS, DTR 2.1.3
DC Load Resistance, receiver 5 k_ ± 2 k_ TxD, DTR 2.1.4
DC Load Resistance, RTS 1.75 k_ ± 500 _ RTS 2.1.4
Source Impedance (Power Off) > 300 _ DSR, DCD,CTS, RxD 2.1.5
Power-off condition interp retation ON condition RTS, DTR 2.1.5
Output Voltage, Open Circuit 25 volts, max.3
3. Absolute magnitude.
RxD, DSR, DCD, CTS 2.1.6
Output Voltage into test load 4
4. Output voltage measured over the entire range of te s t l oad from 3000 ohms to 7000 ohms.
>5 volts;
<15 volts3RxD, DSR, DCD, CTS 2.1.6
Short Circuit Current <100 mA RxD, DSR, DCD, CTS 2.1.6
Transition Characteristics per EIA-232-E RxD, DSR, DCD, CTS 2.1.7