User's Manual

Interface Specification Document Rev. -
Cellular Radio Module CRM4250/4200
Company Confidential
Standard Communications Corp. -6- November 20, 2000
PIN SMBOL I/O DESCRIPTION continued.
15 RXD I Control serial data RX. TTL/CMOS
compatible levels.
16 TXD O Control serial data TX. TTL/CMOS
compatible levels.
17 PROGRAM I Do not connect. Reserved for production.
18 AUXA I/O Reserved for customer applications.
19 AUXB I/O Reserved for customer applications.
20 GND GND Ground.
Note: Portions of this physical interface specification are in the process of being
redefined. Contact the factory for latest status or for special requirements.
3.3 Electrical
3.3.1 Serial Control Link
Tx Data: TTL / CMOS logic level signal output for data from radio to host
Rx Data: TTL / CMOS logic level signal input for data from host to radio
Handshake: none, handshakes implemented in s/w only
3.4. Serial Data Format
type: asynchronous, full duplex
word format: 1 start, 8 data, 1 parity and 1 stop bit
parity: even
bit rate: 9600 baud