Data Sheet

20
3.4.4.3 1-Wire bus enabling
Models featuring 1-Wire bus also feature function for bus enabling/disabling. In default settings, the
value of OW_off variable is set to False, thus the bus is enabled. Setting it to True disables the bus.
3.4.4.4 Master Watchdog (MWD)
Configuration of the Master Watchdog function is done through MWD_enable and MWD_timeout
variable for each group. These variables determine condition for Watchdog activation. Master watchdog
monitors communication with the given group. If there is no communication with the group for the preset
duration (typically communication with the master control program), processor of the group reboots,
outputs of the group are set to default state (previously saved by to NV RAM) and the flag
Was_WD_reboot is set to True. This flag is possible to reset through the variable Clear_WD_boot.
3.4.4.5 Reboot
It is possible to reboot each group by writing True to the variable Reboot. After the reboot the default
settings is loaded.
3.4.4.6 Default state saving
Variable NV_save serves for saving the actual group configuration as a default. This setting (PWM,
PWM_prescale, PWM_cycle, debounce, UART_config, DO, AO, AO_sw, DS_enable, DS_polarity,
DS_toggle) is loaded during the group reboot. Reboot of the group processor can be caused by the
following actions: by MWD function, by writing True to Reboot variable or when
disconnecting/connection power supply.
3.4.4.7 Product version
For correct reading of values stored into two registers it is necessary to exchange high and low byte of
each register.
SWversion
Contains processor firmware version of the given group stored in two bytes, where the high byte is
number of the main version and the low byte is the sub-version.
Num_DI/DO
Each group provides information about number of digital inputs and outputs. Number of inputs is stored
in the high byte and the number of outputs is stored in the low byte.
Num_AI/AO/UART
Number of analog inputs is stored in this variable in the high byte. Number of analog outputs is stored
in the four high bits of the low byte and the number of serial buses is stored in the low 4 bits of the low
byte.
HwVersion
Variable HwVersion contains encoded production mark of the board, its version and its sub-version.
High byte contains the encoded production mark, lower byte is separated into 4 high bits holding the
main version number and the 4 low bits holding the sub-version number.
BoardSerial
Serial number of the board is stored into 2 Modbus registers of size 32 bits.
InterruptMask
This variable serves for interruption detection and it is stored in two bytes. Meaning of each bit
demonstrates the following table.
Bit
Meaning
0
Receive buffer of seriál bus is not empty
1
Serial bus transmission finished
2
Modbus frame receival indication
3
Digital input changed state