User`s guide

HopNet RS-232 Serial ModBus Radio

Serial Commands

These commands affect the serial interface between the modem and the host. The

default settings are 9600 bps and protocol mode 0.

Command Description

sd[?|00-FF]

Set Data Rate Divisor

Data Rate Divisor (hex)

1200 bps = BF

2400 bps = 5F

9600 bps = 17

14400 bps = 0F

19200 bps = 0B

28800 bps = 07

38400 bps = 05

57600 bps = 03

115200 bps = 01

230400 bps = 00

sp[?|00-14]

Set Protocol Mode

00 = point-to-point transparent mode

01 = basic command and data only

02 = command, data and connection notification

04 = WIT2400 protocol mode

05 – 08 = reserved for future use

09 = mode 01 during transmit, transparent receive

0C = mode 04 during transmit, transparent receive

0D – 10 = reserved for future use

11 = transparent transmit, mode 01 during receive

12 = transparent transmit, mode 02 during receive

14 = transparent transmit, mode 04 during receive

Set Data Rate Divisor

Sets the serial bit rate between the modem and the host. This command takes effect

immediately and will require adjusting the host serial rate to agree. Nonstandard rates

may be programmed by entering a data rate divisor computed with the following

formula:

DIVISOR = (230400/RATE)-1

Round all non-integer values down.