Register description

R8: Module ID

Register R8 contains the name for the terminal module.
KM6551-0000: 0x1997 (6551_dec)

R9: Firmware version

Register R9 contains the ASCII coding of the terminal's firmware version, e.g. 0x3141 = '1A'. '0x31' corresponds to the ASCII character '1', '0x41' corresponds to the ASCII character 'A'.
This value cannot be changed.

R12: Minimum data length of a channel

Bits 0 to 6 of the high-order byte specify the minimum number of output data in bits: 000.0000_bin = 0_dec, hence 0 byte.

Bits 0 to 6 of the low-order byte specify the minimum number of input data in bits: 001.1000_bin = 24_dec, hence 3 bytes.
The fact that bit 7 is set indicates that the control and status byte are not mandatory for the terminal function and are not transferred in compact mode.

R16: DIP switch setting

The DIP switch setting is stored in register R16.

R31: Code word register

• If you write values into the user registers without first entering the user code word (0x1235) into the code word register, the terminal will not accept the supplied data.
• If you write values into the user registers and have previously entered the user code word (0x1235) in the code word register, these values are stored in the RAM registers and in the SEEPROM registers and are therefore retained when the terminal is restarted.

The code word is reset when the terminal is restarted.

R32: Channel register (read/write)

IEEE 802.15.4 allows the use of one of 16 available channels. These frequency ranges work without influencing one another. The bandwidth of the signal is 2 MHz and the channel separation is 5 MHz. The channel should be selected such that it does not collide with WLAN or other systems that transmit in the 2.4 GHz range. Permitted settings in register 0...15.
It is permitted to change the channel during operation. The terminal displays the channel change in R33. The frequency channel has been accepted if R32 and R33 are identical.

R33: Channel register (read only)

The terminal acknowledges the acceptance of the channel in this channel. When accepting the new channel in R32, the terminal confirms this by entering the channel in R33.

R38: Watchdog (only activated in slave mode)

The watchdog for the slave is set in register R38. If the value is 0, the watchdog is deactivated. Therefore, no error bit will be set in the event of interrupted communication. The default value is 20_dec. The value from R38 must be multiplied by approx. 20 ms.
Example: R38 = 100 (100 x 20 ms = 2000 ms or 2 sec).

R39: Broadcast mode

Broadcast mode for the broadcast master is activated in register R39. The register is not evaluated by the broadcast slaves. The slaves are “made into” broadcast slaves via the DIP switch.
0x0000: Master-slave- or peer to peer mode (default)
0x4342: Broadcast mode (master)

R40: Scan (only possible in master mode)

The slaves found are entered here if the scan has been activated with the bit CB1.2. Each bit represents a found slave address.

R41: Network ID

Using the network ID you can distinguish between up to 255 radio networks. The KM6551-0000 only accepts telegrams from modules with the same network ID.
Permissible value range: 0...255_dec. The default value is 0_dec.

Operation of several radio networks If you wish to operate different radio networks within the range (e.g. inside a factory hall), distinguishing the networks by the use of different channel numbers guarantees more freedom from interference than if you operate networks with different network IDs on the same channel! Use the network ID to distinguish between different radio networks only if no more free channels are available!

R46: Attenuation of the transmission power

You can attenuate the transmission power of the KM6551-0 using bits 0000 to 7 of register R46. The setting only takes effect when the module is restarted.