SeaLevel 8012e, Руководство пользователя

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© Sealevel Systems, Inc. 8012e Manual | SL9225 12/2022
Writing the Outputs
The output ports are the only ports that can be written. The relays on a standard DIO-16.LPCIe are normally
open. To close a relay a one must be written to the appropriate bit.
Interrupts
Interrupts are not currently supported; however they may be added. Contact Sealevel with your
requirements.
Input Ports
Port A is an 8 bit input port connected to optically isolated input sensors. Each sensor can be used to
interface a voltage input and then sense whether the voltage is on or off. Each sensor is isolated (with
respect to a common ground) from every other sensor and is also isolated with respect to the host PC
ground. This means that signals such as low-level AC line voltage, motor servo voltage, and control relay
signals can be ‘sensed’, or read by the PC, without the risk of damage due to ground loops or ground faults.
Each sensor input pair has a current limiting resistor that is used to limit the input current to the opto-
isolator. The opto-isolator has two ‘back-to-back’ diodes internally. This allows AC or DC signals to be
sensed, regardless of polarity. When the applied voltage is high enough to cause the LED in the opto-isolator
to turn-on, the output of the opto-isolator goes low (0 volts) and the signal is read as a low logic level (binary
0) by the PC. When the input signal is too low to turn on the opto-isolator, the output goes high, and the port
bit is read by the PC as a high logic level (binary 1).
The input impedance of each isolated input is approximately 1500 ohms (factory default). The opto-isolator
requires approximately 2 mA to turn on. The maximum input current is 20 mA.
The input circuits are not intended for monitoring 120-volt AC circuits. In addition to being too
high a voltage for the circuits, it is dangerous to have that high a voltage on the card.