User's Manual

CDR-915 OEM DATA RADIO MODULE
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Revision O INTEGRATOR’S GUIDE
24
CDR-915 D ATA R ADIO
I N-SYSTEM CONFIGURATION
The CDR-915 may be reconfigured while in a host system. This allows the user’s system
to change the source or destination address and group codes on-the-fly, adding great
versatility to the Ack-Back™ delivery mode.
General Structure
The general structure of the protocol for programming the CDR915 radio is as follows:
[0xAA] [command] [checksum] [0x55]
where command consists of byte #1, byte #2, byte #3, ..., byte #n as defined below,
and
where the checksum is an 8-bit checksum (a simple unsigned 8-bit addition of bytes)
of data bytes 1 thru n, 0x55, and
where the checksum does not include the beginning 0xAA, itself, or the ending 0x55.
Numbers preceded by “0x” are hexadecimal. All others are decimal.
The DTR pin must be raised prior to sending any commands to the radio. Once a
complete command has been sent to the radio, the DTR pin should be immediately
lowered. If a read command of some sort was issued, the device should be ready to
receive the information immediately. If a Write Command was issued, the device must
allow 250 milliseconds for the radio to reboot itself with the new values before any
other commands can be issued.
As bytes are sent to the radio, each byte will be immediately echoed back to the sender
for confirmation that the radio received the byte.
When any data is being read from the radio, the device should simply read in the data
without echoing the bytes back to the radio.
EEPROM values are loaded on power-up. Values written to RAM will be used until the
radio loses power.