Version List

Transceiver module TRX433-10C2 / TRX868-10C2 (Vers. 1.0E) 6
General information
Serial Interface (RS232)
There is a serial bidirectional full duplex interface available to communicate with the transceiver module. The
data are transmitted and the transceiver module is configured over the same interface. You can choose
between data mode and configuration mode with the MODE pin.
Data mode (MODE Pin = Low)
When the transceiver module receives data over the serial interface then those are automatically transmitted
to all transceivers with the same configurations (frequency, RF data rate etc). Then those transceivers output
them immediately over the serial interface after a few milliseconds. The baud rate for the RS232transmission
can be set from 1.2kbaud to 115.2kbaud 6 .
Configuration mode (MODE Pin = High)
The transceiver module is configured over the serial interface. There is a comprehensive command set
available. The last configuration will stay saved in the internal EEPROM if the accordant bit for saving in
EEPROM is set. The configuration can occur in any baud rate from 1.2kbaud to 115.2kbaud 6 (the baud rate
is detected automatically in the configuration mode).
Radio transmission
In the data mode, all the data which was received by the transceiver module over the serial interface are
transmitted autonomous via radio. The transceiver module completely does the coding and decoding of the
radio transmission. However, you can adjust the radio transmission to your own needs with help of a few
simple commands. The following configurations can be done:
Frequency selection
There are 139 frequencies in 433MHz–band respectively 159 frequencies in 868MHz–band available, in
each case in the 12.5 kHz–channel spacing. The frequency can be chosen irrespectively of the adjusted RF
data rate. Make sure that on systems with several used frequencies, the frequency separation is at least the
same as the occupied channels of the adjusted RF data rate (see table 1). This frequency separation has to
be raised as high as possible for a better range.
RF data rate
The RF data rate can be chosen from 1.2kbits/s to 38.4kbits/s 7 according to requirements. The smaller the
RF data rate is chosen, the higher is the radio range between the transceiver modules. RF data rates >
19.2kbits/s are possible but they require an accordant dimensioned loop filter respectively a change in
assembling. Through this change, the sensitivity of the receiver with low RF data rates is reduced. The basic
model TRXnnn-10C2 is assembled with loop filters for max. 19.2kbits/s.
Further radio transmission configurations to the chosen RF data rates are made automatically by the
transceiver modules. These configurations for the different possible RF data rates can be found in table 1.
RF data rates Coding Modulation FM-deviation IF-bandwidth Occupied
channels
1.2 kbit/s
2.4 kbit/s
4.8 kbit/s
9.6 kbit/s
19.2 kbit/s
38.4 kbit/s 7
Manchester GFSK
Manchester GFSK
NRZ GFSK
NRZ GFSK
NRZ GFSK
NRZ GFSK
NRZ GFSK
NRZ GFSK
+- 2.025 kHz
+- 2.025 kHz
+- 2.025 kHz
+- 2.025 kHz
+- 4.050 kHz
+- 4.950 kHz
+- 9.900 kHz
+- 19.80 kHz
9.6 kHz
12.3 kHz
9.6 kHz
12.3 kHz
19.2 kHz
25.6 kHz
51.2 kHz
102.4 kHz
1 x 12.5kHz
1 x 12.5kHz
1 x 12.5kHz
1 x 12.5kHz
2 x 12.5kHz
4 x 12.5kHz
8 x 12.5kHz
12 x 12.5kHz
Table 1 RF data rate with corresponding further configurations can be chosen.
Comment
433 MHz
868 MHz
433 MHz
868 MHz
6
115.2kbaud requires a 16MHz µP clock frequency
7
RF data rate > 19.2kbits/s requires a modification of the loop filter, therefore a change in assembling and a
16MHz µP clock frequency