Configuring jumper settings – Contemporary Control Systems CANISA User Manual
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CONFIGURING JUMPER SETTINGS
Power Selection
A set of four jumpers, labeled POWER, offers the choice between powering
the CANISA transceiver circuitry from the host computer or from the
CANbus. By default the jumpers are set to INT. To power the transceiver
from the CANbus, move all four jumpers to the EXT setting.
DeviceNet Reverse Voltage Protection
By default, diode D1 protects the CANISA from overvoltage which would
occur if the DeviceNet power connections were accidentally reversed. This
protection results in the CANISA ground being about 700 mV different from
the CAN ground. If desired, the CANISA ground potential can be made
equal to the CAN ground by installing a jumper on JP7.
Termination
If the CANISA is located at the end of a trunk, line-matching impedance is
required. A 121-ohm resistor is supplied for this purpose. If a different
impedance is needed, jumper JP8 should be removed and the alternative
impedance connected to screw terminals CAN_H and CAN_L.
Interrupts
Jumper block JP6 makes available all possible interrupt selections.
Interrupt 5 has been chosen as the default.
I/O Address Map
The CANISA has two modes of operation—BasicCAN and PeliCAN—that
affect how the I/O space is defined. I/O addressing is set with jumper block
JP9 using jumpers S0–S4 and RA. By default, jumper RA (Range) is open
causing the I/O space to be 32 contiguous bytes in size. This setting is used
in BasicCAN, but may also be used in PeliCAN. For full PeliCAN
functionality, jumper RA must be installed, extending the I/O space to 128
contiguous bytes.
The CANISA uses an I/O space within the range 0x000–0x3FF as illustrated
in Tables 1–3. Regardless of the RA setting, jumpers S0–S4 are used to
select the address at which the I/O space begins. The default setting is
0x300. Remember, RA determines only the size of the I/O space: 32 or 128
bytes.
An unused jumper may be left on the board with no effect, by attaching the
jumper to only one of the two pins that constitute a jumper pair.
TD990520-0I
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