Inverting the Logic Sense of the Opto-Isolation:
It is often useful to invert the logic sense of the Galil outputs.
Commonly used opto-isolation modules such as those by OPTO-22 or
Grayhill operate with negative true logic. With this type of module, it is
desirable to drive these modules with an open collector output.
Furthermore, it is important for the default and power-on state of these
outputs to be non-active. Using the opto-isolation option, this can be
easily provided by inverting the output. If the logic sense has been
inverted, when the outputs are set low (using the command CB) the opto-
isolation output will be in-active. When the outputs are set high (using the
command SB), the opto-isolation output will be active (sink current).
To invert the opto-isolation outputs, remove the resistor pack on
RP3, turn the resistor pack around 180 degrees and replace it. This places
pin 10 of the resistor pack into pin 1 of the socket on the ICM-1900.
Connections to the opto-isolated outputs do not need to be modified.
This configuration can be specified when ordering the interconnect
by using the designation INVOUT (ex. ICM-2900 OPTO INVOUT).
ISO OUT POWER (ICM-1900,PIN 19)
OUT POWER (ICM-2900)
OUT[x] (66 - 73)
ICM-1900 / ICM-2900
CONNECTIONS
(-INVOUT OPTION)
RP4=10K OHMS
FROM
CONTROLLER
OUT[x] TTL
LOAD (OPTO-MODULE, ETC)
ISO POWER GND (ICM-1900,PIN 35)
OUT GND (ICM-2900)
This point connected to
GND when resistor pack,
RP3, is inverted
Configuring for High Side Operation (-HISIDE option):
Galil can provide the opto-isolation configured for applications
that require a High Side Drive Circuit. This type of configuration is
denoted as HISIDE and must be specified when the Interconnect Module
is ordered.
In this configuration, the load is connected to ground and the
output delivers current - see diagram. With the HISIDE configuration,
the opto-isolated output can source 24ma of current and the maximum
