For developing and testing the
Cogent drivers, we have set up our test equipment to simulate
typical field applications. Although your situation will differ
from this, you can use this scenario as an example for setting up
your driver.
A.1. The Test Environment
The environment of the test scenario looks like this:
The test scenario has a test application that sends commands
to and handles input from the Cogent Driver. The driver is
connected to the card, which is connected by a fieldbus to the Field
IO: a WAGO-I/O-SYSTEM 750
Fieldbus Coupler. (Cogent software works with any fieldbus
hardware; we chose this equipment because it suits our needs.) The
Fieldbus Coupler is connected to several digital and analog input
and output modules. Each of these modules is wired to a test panel
with several input and output devices, such as knobs, meters,
switches, lights, etc., as explained below.
- A Fieldbus Coupler connects the I/O modules to the
fieldbus. The test scenario can be used with any fieldbus protocol
simply by changing the Fieldbus Coupler. The test panel is
currently set up to handle Interbus, Profibus, and DeviceNet
protocols. Whenever the Fieldbus Coupler is changed, the Protocol
Selector knob on the test panel must be changed to the correct
protocol before powering up.
- A 2-Channel Analog Input Module is connected to the two
volume knobs on the test panel. The corresponding data points
in the driver are named volumeLeft and
volumeRight.
- A 2-Channel Analog Output Module is connected to the two
meters on the test panel. The corresponding data points in the
driver are named meterLeft and
meterRight.
- A Supply Module that supplies power to the digital modules.
- A 4-Channel Digital Input Module is connected to the
thumbwheel. Each of the 4 channels takes one bit. The 4 bits
are used to represent the numbers
1-10 on the thumbwheel.
The corresponding data point in the driver is named
thumbwheel.
- A 2-Channel Digital Input Module is connected to the two
push buttons. The corresponding data points in the driver are
named pushon_pushoff and
pushbutton.
- Two 2-Channel Digital Input Modules are connected to the
four toggle switches. These are not currently in use, and have
no corresponding data points in the driver.
- Three 2-Channel Digital Output Modules are connected to
the red and green lights. The corresponding data points in the
driver are named GreenLight1,
GreenLight2, RedLight1,
RedLight2, RedLight3 and
RedLight4.
- A 2-Channel Digital Output Module with diagnostics is
connected to the Sonalarm and the counter. The corresponding
data points in the driver are named sonalert
and counter. The diagnostics feature of the
module uses red lights to indicate short-circuit or open-circuit
errors. The toggle switch on the panel cuts power to the
sonalarm, to test the open-circuit error. The corresponding
data points in the driver for the error circuits are named
sonalertFault and
counterFault.
- An End Module
