| xPC Target | |
The PCI-DDA08/16 has two 8255 chips (1,2). Each chip has three ports (A,B,C). Each port has a maximum of 8 digital I/O lines that can be configured as inputs or outputs.
Use a separate diver block for each port. By selecting the digital output driver block, the port is configured as output.
Scaling Input to Output
| Hardware Output |
Block Input Data Type |
Scaling |
| TTL |
double |
< 0.5 = TTL low > 0.5 = TTL high |
Driver Block Parameters
Channel vector -- Enter numbers between 1 and 8 to select the digital output lines used with this port. This driver allows the selection of individual digital output lines in any order. The number of elements defines the number of digital lines used.
For example, to use all of the digital outputs for one port, enter
Number the lines beginning with 1 even if the board manufacturer starts numbering the lines with 0.
Port -- From the list choose either A, B, or C. The I/O board has two 8255 chips with 3 ports. The Port parameter defines which port of the 8255 chip is used for this driver block. Each port has a maximum or 8 digital lines that can be configured as inputs or outputs depending on which driver block is chosen. In each case, one block is needed for each port.
Reset vector -- The reset vector controls the behavior of the channel at model termination. Enter a scalar or a vector that is the same length as the channel vector. If you specify a scalar value, that setting is used for all channels. If you specify a value of 1, the corresponding channel is reset to the value specified in the initial value vector. If you specify a value of 0, the channel remains at the last value attained while the model was running.
Initial value vector -- The initial value vector contains the initial values (0 or 1) of the output channels. Enter a scalar or a vector that is the same length as the channel vector. If you enter a scalar, that value is used for all channels. The channels are set to these initial values between the time the model is downloaded and the time it is started.
Chip -- From the list choose 1 or 2. The Chip parameter defines which of the two 8255 chips is used.
Sample time -- Enter a base sample time or a multiple of the base sample time.
PCI Slot (-1:autosearch) -- Enter a number between -1 and n. If only one board of this type is physically present in the target PC, enter
If two or more boards of this type are physically present in the target PC, enter the bus number and the PCI slot number of the board associated with this driver block. Use the format [BusNumber, SlotNumber]. To determine the bus number and the PCI slot number, type
| | PCI-DDA08/16 Digital Input | PCI-DIO24 | |