Adept EX SmartContoller - Manual (Page 74)

Chapter 6: sDIO Module
NOTE: The off-state current range exceeds the leakage current of sDIO outputs. This guarantees
that the inputs will not be turned on by the leakage current from the outputs. This is useful in sit-
uations where the outputs are looped-back to the inputs for monitoring purposes.
sDIO Outputs
The 32 output channels are arranged in four groups of eight. Each group is isolated from the
other groups and is optically isolated from the sDIO circuitry. The eight outputs within each
group share a common power supply and a common ground.
The outputs are accessed through the two female 44-pin D-sub output connectors on the front
of the sDIO module. Each connector provides access to two output groups. Each group
requires 19 pins: 8 output signals, 1 test signal, 9 power supply (all tied together), and 1 power
supply ground reference. When an output is on, current will flow in through the power supply
pins and out through the output pins. This type of output is considered sourcing, that is, in the
On condition, current flows out of the output pin. See the figure Typical sDIO Output Wiring
on page 77 for details on typical digital output wiring.
Testing sDIO Outputs
Like many solid-state I/O systems, when an output is off, a small leakage current will flow out
of the output. This will raise the potential of the output to the power supply voltage level if
there is no load. With a load connected, the output will function normally. However, if you
need to test the output with a voltmeter with a load disconnected, you will get a false reading.
The test signal provides a bias that can be used as a pull-down resistor for system-level trou-
bleshooting. When this is connected to an output, the output will assume the ground potential
when it is off.
sDIO LEDs
A pair of two-color LEDs on the sDIO module indicate link status over the IEEE 1394 con-
nection and system status. The upper LED lights green when an IEEE 1394 connection is estab-
lished. The lower LED blinks green when the software is active and switches to solid green
after the controller software has found and configured the DIO block. The lower LED lights
solid red whenever an output fault (excessive current or temperature) is detected on any of the
32 outputs. Refer to the following table for information about the LEDs and the figure sDIO
Connectors and Indicators on page 65 for information on their location.
NOTE: A fault indication is the result of an over-temperature or over-current condition on one or
more of the outputs, usually due to a short-circuit. As a result, the output driver IC will oscillate on
and off as the chip tries to drive the load.
Note that this red fault LED is active only when:
l
An extended output (for example, a SIGNAL in the range of 33 to 64) has been turned
on by an eV+ command.
l
An activated output has a thermal-overload problem, usually due to a short in the
user’s wiring from the output pin to the user’s ground.
Adept SmartController EX User’s Guide, Rev. B
Page 74 of 96