PIA-8255 Introduction

The Tanner Soft PIA8255 WinLok driver is a System Based Driver for 8255 compatible parallel I/O cards. It is NOT the same as the original Parallel Sensor software that is built into the WinLok program to drive the same cards. The inputs from this new driver map into the same serial I/O space as other system based inputs such as the Digitrax DS-54, Märklin s88, Lenz LR-100 etc., and the outputs are controlled by the same Switch/Signal Solenoid Device commands that are used for other output devices such as stationary decoders.

This new driver enables modelers that do not have DCC, or who's DCC system does not support the commonly available DCC input or output devices to still have the advantages of using WinLok for layout control, and/or to be able to develop a fully computer based CTC system. Using the WinLok MultiDrive driver module allows for full integration of both serial input devices and parallel I/O based devices into one seamless system. The user can easily use a digital I/O card for occupancy detection and signal operation, with the track switch position and feedback information being taken care of with a DS-54 or similar stationary decoder.
 

PIA-8255 Driver installation

2. If you are using more than just the PIA8255 driver as we are in this example, then first you will need to install the MultiDrive driver. Go to General - General Setup and enter MULTIDRV.DRV as the Driver. Check any of the Start Up Sequences you may desire, and then click OK.

Now go to the MultiDrive drop down entry on the toolbar and click on Driver Assignment. Choose Insert to add each driver that you will need. Select each driver in turn and choose which WinLok addresses will be used by that driver. In this example we will reserve the first 18 Locomotives, the first 144 Solenoid devices and the first 9 banks of Feedback Modules for the PIA8255 driver.

Next we will reserve 100 Locomotives (19-118) 32 Solenoids, and 2 banks of Feedback Modules for our Digitrax driver.

3. As mentioned above in the introduction, the new PIA-8255 driver no longer uses the original internal WinLok parallel software. Instead it interacts with the system exactly the same as a set of serial system feedback sensors. To install the 144 port ACL-7122 you will need to define at least 9 System Based Serial 16 Input Feedback Modules. (The Märklin s88 sensors are used as the default type.) In our setup example we will also be installing some Digitrax DS-54 modules, so setup for at least 10 feedback sensor modules. (9 for the ACL-7122, and 1 for the DS-54) To do this, go into the Database drop down list and select Feedbacksensors. Select Serial, and then enter the total number of 16 input feedback module groups that you will need. Check the "Use Feedbackmodules" check box if you want the system to check the status of the sensors as soon as track power is turned on.

4. Next we need to choose what sections of the ACL-7122 will be used for input devices, and which sections will be reserved for output. Use the accompanying worksheets to determine these assignments. (ACL-7122 Input worksheet - ACL-7122 Output worksheet) Note that any circuit ID (port and byte) may only be used once. If for example you choose to use section 1A for input, then you should scratch through section 1A on your Output assignment worksheet. In a like manner, if a section is used for output, then you should scratch it from your Input assignment sheet. The assignment addresses are fixed by the driver logic, so you may change any Circuit ID from Input to Output without affecting any of the other assignments on the board. In other words, if you assign 1A as an input, then ser(1,1) - ser(1,8) will become active as inputs, but SWI(1) - SWI(8) will not exist. If later you decide to reassign section 1A as an output device, then ser(1,1) - ser(1,8) will become inactive as inputs, but SWI(1) - SWI(8) will become available as outputs.
 

5. Once your assignments are completed, go to the PIA8255 driver setup. Set the port address A for the first section (#1) to the primary hardware address that you used in your hardware setup. (E.g. 2C0) Check the "use port" check box. Next check the radio buttons for each of the three ports A-C to select the mode and polarity of each. setting up the desired modes for each port. Proceed through each of the 6 sections setting each with an address that is 4 higher than the previous one, (e.g. 2C0, 2C4, 2C8, 2CC, 2D0, 2D4) and choosing the required modes for each one. Be sure to download the latest version of the PIA8255 driver here as the original driver had a minor bug that affected this step.

 

6. Once you have setup your ACL-7122 or other PIA-8255 device you must enter a new item into the database to use it for outputs. I recommend that you enter the Article Number as "PIO" or "PIA". The Item Name is "8255 I/O Board". An example for Manufacturer is "NuDAK ACL-7122". Define the category as "Switch".

7. Next go to the Switches and Signals database and make an entry for each SWI output that you have defined on your worksheet as being required. The "Digital-Nr" will be the same SWI() number shown on your worksheet. The "Kat.-Nr" will be the name that you just entered in step #6. You may also add a comment for each entry. For a comment I just note the Circuit ID for each group. You will find the Copy command is very useful for this operation due to the large number of entries to be made.

Once all of the above steps are taken, you may start actually using your new digital I/O device to input from or output data to your layout using WinLok SWI() or ser() commands.