High Country Tek emc-3L - Manual (Page 87)

8 Application Notes
8.1 CAN Bus Configuring
DVC modules communicate using the CAN Bus protocol and wiring scheme. Each module (including the
master DVC710) has an identifying CAN Bus MAC ID number. The two digits number MAC ID of each module
must be unique. MAC ID numbers can be assigned in two ways. Using the Programming Tool each module in
your project has a configuration window that contains a MAC ID entry field. Generally the default values will not
need to be changed. The second method is to use the Program Loader Monitor connected to an individual
module’s RS232 port to specify the MAC ID number.
It should be noted that the CAN Bus communication system gives preference to modules with the lowest MAC
ID number when multiple modules are trying to use the bus simultaneously. Therefore, systems generating a lot
of CAN Bus traffic should assign the lower MAC ID numbers to the most critical modules. A display module for
instance could have a high MAC ID number.
8.2 DVC710 Supply Power
To use a DVC710 in the programming examples or in your system you need to be able to power up the
DVC710. Refer to the DVC710 hardware manuals for details on this. Basically you will need to supply +9vdc to
+30vdc capable of driving 250mA to the module. Connect the power supply leads to pins A1 or A2 and a
ground or power common connection to pin F1 on the 18-pin connector of the DVC710
8.3 Driving Alarms from outputs
When driving a alarm from a bang bang output. When the output is turned off, the alarms still emit a low level
signal. Turning off the .OpenDisable bit,allows enough current to flow to allow the alarm to sound.
Solution:
The High Side outputs have a 75K pull up resistor to the supply voltage in order to allow for open detection.
This would allow 160uA and 320uA respectively for 12/24 volt systems to flow from out High Side Outputs.
Therefore, adding an external pull down resister to the output or other isolation would help.
P/N: 021-00163, Rev. A.0 - for V5.2 Tools Page | 87