This CDR-915L is a data transceiver operating in the 902-928 MHz ISM
band. The unit is designed to operate under Part 15.249 of the FCC rules
and regulations and is designed as an OEM module for professional
integration into other products or field devices. When installed using an
approved antenna, the user need only ensure that the appropriate FCC
information is clearly visible on the outside of the integrated product. This
label should contain one of the following phrases to be considered valid.
1. "Contains Transmitter Module FCC ID: PHO-CDR915LX" or
2. "Contains FCC ID: PHO-CDR915LX
For integration into products sold in Canada, the label should
read as follows.
Contains Transmitter Module IC 4315A-CDR-915LX
The term “IC:” before the certification/registration number only signifies
that the Industry Canada technical specifications were met.
Caution: If this radio is integrated into another product, the user is
responsible for complying with the external labeling requirements as directed
in the FCC Rules and Regulations part 15.19. To avoid the need to obtain
additional certification, the user should only use antennas that have been
tested and approved for use with this radio module.
The unit operates on 62 discrete frequencies within the ISM band, each
frequency about 400kHz apart. Using a frequency agile phase-locked loop
synthesizer, the radio is able to operate on any of 62 non-interfering
channels.
The radio is connected to a host device using a 10-pin SIP header. This
connection provides the radio with the required DC power source, allows it to
be programmed and configured and provides all I/O lines for both an
asynchronous serial as well as an SPI interface.
The CDR-915L is supplied with an easy-to-use Windows™ configuration
program. The configuration program allows the user to control the operation
of their radio network.
Installing
The configuration software does not require an installation. Simply run it
from the CD labeled “CDR-915L Tools” or copy it onto another drive. Start
the program by locating and double clicking on the “Programmer” icon. This
will launch the configuration program and display the screen below.
Click on the “PC Settings” tab, then select which COM port will be used to
connect to the data radio. As shown below, COM1 thru COM4 are available.
This setting will be retained the next time the configuration program is run.
Getting Started
To configure the radio, click on appropriate tab to select the radio type being
configured. Then select the radio Communications Port. The default setting
is for asynchronous serial mode, UART (Universal Asynchronous
Receiver/Transmitter). The default baud rate is 9600 bits per second. The
interface baud rate can be set to standard values between 2400 and 57600
as shown on the following page. This mode supports 8 data bits, 1 stop bit
and no parity.
The radio has been designed to be very versatile in its addressing functions.
Each radio unit has its own identifier consisting of a group number and
address number.
The Source Group specifies which group of radios the unit being configured
belongs to. The Source Address specifies the address within that group that
uniquely identifies this radio. The radio will decode packets containing a
Destination Group and Address matching its own. With the exception of
broadcast messages, all others will be ignored.
Broadcast messages are those messages where the destination address is 0
and the group is the same as the radio receiving it, or those messages
where the destination address and group are both 0. When the destination
group is set to 0, all radios in all groups will decode the packet.
Likewise, the Destination Group specifies which group of radios the
transmissions will go to. The Destination Address specifies the individual
radio within that group that will receive the message.
Channel
The Channel selects the frequency the radio will transmit and receive on.
There are 62 channels available for the use of multiple networks or to avoid
interference. Radios must be on the same channel to communicate.
TX Hold Off Time
TX Hold Off Time sets the amount of time that must elapse after the last
byte to be transmitted is received by the radio before a transmit packet will
be initiated. Setting this value higher will prevent numerous small packets
from being sent when the transmit data is not continuous. The default
setting will be adequate for most applications.
Acknowledgement (Ack-Back™)
The CDR-915L has powerful, built-in path management features designed to
make OEM integration quick and easy. Activating packet acknowledgement
will virtually guarantee all data transmitted is received. Any packet
transmitted by the CDR-915L is then acknowledged by the receiving radio.
If any packet is not acknowledged, the transmitting radio will resend the
data. While reducing throughput, this feature also handles missed
transmissions as well as performs path management, allowing full duplex
communications.
The numeric value populated in the Retries field specifies the number of
attempts the radio will make in trying to resend unacknowledged packets.
The value in the Timeout field determines how long the radio will wait for the
acknowledgement before resending. (See Hardware Timing for more
information)
Number of Repeaters
The range of the CDR-915L may be extended by using repeaters. Repeater
modules receive data packets on one group code and retransmit the packet
on another group code. For example, a repeater configured with group
codes 3 and 4 will translate the following packets and retransmit them as
follows:
• A packet received with a destination group code of 3 will be received
and retransmitted with a destination group of 4.
• A packet received with a destination group code of 4 will be received
and retransmitted with a destination group of 3.
This method of group code translation guarantees that data is transferred
through the repeater and not directly between radios.
When the CDR-915L is in Ack-Back™ mode and there are repeaters in the
system, the amount of time needed to receive packet acknowledgements
increases. By specifying the number of repeaters in the Configuration
program, this delay is calculated and the radio is updated correctly. Always
populate this field with the maximum number of chained repeaters in the
system.
The CDR-915L has powerful path management tools to help ensure
successful field installations. The Path Management window has two modes,
Continuous and On Sync.
The Continuous mode allows the installer to look at competing signals on the
radio’s channel and determine if there is a potential interference problem.
Running in this mode for an extended period of time will show the installer
the level of the strongest signal seen by the radio. The solid indicator needle
indicates the current signal level being received while the dashed indicator
needle shows the strongest signal received. Clicking the Stop button will
reset the dashed indicator.
The On-Sync mode allows the installer to look only at radio transmissions for
CDR-915L radio. When packets are received, the transmission’s current
and maximum signal strength is displayed along with the packets’ source
group code and address. This allows the installer to ensure there is
adequate signal strength with enough fade margin to guarantee reliable
operation. Signals in the green area are considered very reliable, the yellow
area are marginally reliable and the red area are considered not reliable.
The graph will display information for a maximum of 16 radio addresses. As
new addresses are received, they will replace the oldest ones in the graph.
The signal received last is indicated by a cross hatch in the bar. Clicking on
the Stop button will reset the graph information.
The CDR-915L has been designed for easy field upgrades. Using the RS-232
Serial Adapter board, a DR915 Programming cable, a standard Serial
Configuration cable and a current version of the CDR-915L/LT Configuration
program running on the user’s PC, the radio can be re-flashed with new
operating code. Special customer code can also be loaded in this manner.
With the radio mounted on an RS232 Serial Adapter board, connect a
program upgrade cable from the programming connector, J4, on the Adapter
board to the parallel port on the PC. Connect a standard DB9 male-tofemale serial cable from the Adapter board’s DB9, J2, and to the serial port
on the PC. Power the Adapter board using the supplied 12-volt wall module
connected to the Adapter board’s power jack, P8.
Using the CDR-915L/LT Configuration program, click on the Flash tab.
Select the software version from the Software Version drop-down box and
then press the Program Flash button. The Configuration program will then
read the setup information from the radio, upgrade the radio code and
reload the original configuration.
PIN FUNCTION
1 Ground
2 CTS
3 DTR
4 Receive Data
5 Transmit Data
6 Reset
7 SPI Clock
8 SPI MISO/Fail
9 SPI MOSI/Sending
10 VCC
PIN 1 – Ground
Power and signal ground for the data radio.
PIN 2 – CTS
Clear to Send. This line will be low when the radio is ready to accept
data to transmit. When the radio raises this line, the user application
must cease sending data to the radio or a buffer overflow may occur,
resulting in a loss of data.
PIN 3 – DTR
Data Terminal Ready. This line is used to place the radio into
configuration mode. It should be held low for normal operation.
PIN 4 – Receive Data
This is data received by the radio and sent out to the user device. The
data format is a standard, asynchronous stream at the user-set baud
rate with one start bit (low) followed by eight data bits and one stop
bit (high). This is a TTL-level interface. Applications requiring RS-232
must use an appropriate interface circuit or a CDR-915L RS-232
interface board.
PIN 5 – Transmit Data
This is the data sent by the user device for the radio to transmit. The
data format is a standard asynchronous stream at the user-set baud
rate with one start bit (low) followed by eight data bits and at least
one stop bit (high). This is a TTL-level interface. Applications
requiring RS-232 must use an appropriate interface circuit or a CDR915L RS-232 interface board.
PIN 6 – Reset
Taking this pin low will reset the radio’s microcontroller. For normal
operation, this pin should be left open.
PIN 7 – SPI Clock
This pin is used for updating the code in the radio.
PIN 8 – SPI MISO
This pin indicates a failure to complete an transmission while in AckBack™ mode. This pin is also used for updating the code in the radio.
PIN 9 – SPI MOSI
This pin indicates the radio is attempting a transmission while in AckBack™ mode. This pin is also used for updating the code in the radio.
PIN 10 – VCC
This is power to the radio. It should be 7.5 to 15 vdc.
The CDR-915I-232 is a serial adapter board that allows the user
to easily connect to the CDR-915L Data Radio using a standard
DB-9 serial cable. The interface board also provides visual
indication of data coming from and going to the user-connected
equipment.
Yellow indicates the radio is ready to accept data from the userconnected equipment.
Green indicates data is being sent from the radio to the userconnected equipment.
Red indicates data is being sent from the user-connected
equipment to the radio.
DB-9 Pin Out (RS-232)
PIN 1 – DCD (Data Carrier Detect) is always held high by the radio.
PIN 2 – RD (Receive Data) is serial data from the radio to the user device.
PIN 3 – TD (Transmit Data) is serial data from the user device to the radio.
PIN 4 – DTR (Data Terminal Ready) i ndicates the user device is ready to send
data to the radio for transmission. When this line is high, the radio
will transmit any data across the RF network. When this line is low,
the radio will process the data as commands.
it should be tied to PIN 1.
PIN 5 – GND (Ground) is the interface common.
PIN 6 – DSR (Data Set Ready) is always held high by the radio.
PIN 7 – RTS (Request To Send) is not connected on an RS-232 Interface
board.
PIN 8 – CTS (Clear To Send) is used to indicate to the user device that the
radio can accept more data. When this line is high, the user device is
clear to send more data. When this line is low, the user device should
not send data. (This line may be ignored at baud rates of 2400 and
4800 bps. The TX Packet size should be changed to 150 bytes to
prevent a buffer overflow.)
PIN 9 – RI (Ring Indicator) is not connected on an RS-232 Interface board.
When configured for Ack-Back™ mode, the radio will attempt to resend packets that are not acknowledged as
received by the destination radio. While this virtually guarantees that data will be correctly transmitted, there is still
the possibility that the destination radio is unavailable. Because of this, the CDR-915 supplies hardware indication
of the success or failure of Ack-Back™ packets. (See Radio Hardware Interface for pin definitions)
Shown below is an example of the hardware handshaking for a successful Ack-Back™ transmission. The TX trace
identifies the actual transmission attempt and is internal to the radio. Th e SNDING trace is the handshake signal on
Pin 9 of P2. This signal goes high when the transmit attempt is made and stays high until the acknowledgement
packet is received from the destination radio.
If and acknowledgement is not received within the Ack-Back™
Timeout time, the radio will resend the packet up to the Ack-
Back™ Retries setting. If an acknowledgment is received during
one of the retries, the SNDING signal will return low, indicating a
successful transmission. If there is no acknowledgement after all
retry attempts, the SNDING line will return low and the FAIL line
will go high to indicate a transmission failure
The CDR-915L may be reconfigured while in a host system. This allows the users 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 DR915L radios 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.
The format of the data bytes for sending a command to the radios is as follows:
Read command:
- 0x01 (1 byte)
- memory select (1 byte) (0 = read from EEPROM, 1 = read from RAM)
- beginning address (high byte) (1 byte)
- beginning address (low byte) (1 byte)
- number of bytes to be read (1 byte)
Write Command:
- 0x02 (1 byte)
- memory select (1 byte) (0 = write to EEPROM, 1 = write to RAM)
- beginning address (high byte) (1 byte)
- beginning address (low byte) (1 byte)
- number of bytes to be written (1 byte)
- byte #1 to be written
- byte #2 to be written
- byte #3 to be written
- byte #n to be written
Path Management:
-0x03 (1 byte)
-mode (1 byte) (0 = off, 1 = every 250ms & on sync, 2 = on sync)
This command returns a series of packets 6 bytes long. The packet structure is as follows:
-0xAA (1 byte)
-counter (high byte) (1 byte)
-counter (low byte) (1 byte)
-source group (1 byte)
-source address (1 byte)
-0x55 (1 byte)
Read Model Command:
- 0x04 (1 byte)
This command returns an ASCII string 15 bytes long.
Read Software Version Command:
- 0x05 (1 byte)
This command returns an ASCII string 15 bytes long.
Read Serial Number Command:
- 0x06 (1 byte)
This command returns 4 bytes with the least significant byte first.
Changes or modifications to the CDR-915L not expressly approved by Coyote
DataCom, Inc. could void the user’s authority to operate this product.
Note: This equipment has been tested and found to comply with the limits
for a Class B digital device, pursuant to part 15 of the FCC Rules. These
limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates and can
radiate radio frequency energy and, if not installed and used in accordance
with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct
the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that
to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.