Configuring I/O Items
Original instructions
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Overview
The final task in this example is to add I/O items to the configuration of the STB NIC 2212 and its I/O modules. To accomplish this:
I/O Item Types and Sizes
The goal is to create a collection of input items and output items that equal the input size and output size specified for the STB NIC 2212.
The Control Expert Device Editor provides great flexibility in creating input and output items. You can create input and output items in groups of 1 or more single bits, 8-bit bytes, 16-bit words, 32-bit words, or 32-bit IEEE floating values. The number of items you create depends on the data type and size of each item.
Mapping Input and Output Items
Use the Fieldbus Image page of the I/O Image Overview window in the Advantys configuration software to identify the number and type of I/O items you create:
Step
Action
1
In the Advantys configuration software, select Island → I/O Image Overview. The I/O Image window opens to the Fieldbus Overview page.
2
Select the first cell (word 1, cell 0) in the Input Data table to display—in the middle of the page—a description of the cell data and its source module.
3
Make a note of the word, bit(s), module and item information for that cell.
4
Repeat the above steps for each cell that contains an S or an integer.
NOTE: The fieldbus image presents input and output data in the form of 16-bit words (starting with word 1). You need to rearrange this data for the Control Expert Ethernet Configuration Tool, which presents the same data in the form of 8-bit bytes (starting with byte 0).
NOTE: When you create items, align items of data type WORD and DWORD, as follows:
  • WORD items: align these items on a 16-bit boundary
  • DWORD items: align these items on a 32-bit boundary.
This example shows you how to create input bytes and output bytes. To use space efficiently, this example creates items in this sequence:
Open the Items configuration in Control Expert.
Creating Input Bit Items
Create input bit items for the STB NIC 2212 example, beginning with discrete inputs for the NIC 2212 status:
Step
Action
1
Select the Input (bit) tab and follow directions to create input bit items. Use the default root name to represent the device status (DDI3232_in_data) in the Default Items Name Root field.
2
In the Items List, select the first two rows in the table. (These rows represent bits 0-1 in byte.)
3
Click the Define Item(s) button to open the Item Name Definition dialog box.
NOTE: An asterisk (*) in the Item Name field indicates that discrete items with the same root name are created.
4
Accept the default Item Name and click OK to create two discrete input items.
5
Click Apply to save the items and leave the page open.
6
Repeat these steps for each group of discrete input items you need to create.
Creating Input Items
To create input items for the STB NIC 2212 example, begin with an input data byte that contains the low byte status for the STB NIC 2212 module:
Step
Action
1
Select the Input tab.
NOTE: In this example, both the Offset/Device and Offset/Connection columns represent the byte address. The items you create are 8-bit bytes or a 16-bit words.
2
Enter NIC22212_01_LO_st in the Default Item Name Root field.
3
Select a single row at byte 8.
4
Click the Define Item(s) button to open the Item Name Definition dialog box.
5
Select Byte as the New Item(s) Data Type.
6
Click OK to create the byte.
7
Click Apply to save the items and leave the page open.
8
Repeat these steps to create new byte or word input items.
Creating Output Bit Items
Create output bit items for the STB NIC 2212 example, beginning with two output bits for a STB DDO3200 module:
Step
Action
1
Select the Output (bit) tab.
NOTE: In this example, both the Offset/Device and Offset/Connection columns represent the byte address of an output. The Position in Byte column indicates the bit position (within the byte) of each discrete output item.
2
Enter DDO3200_out_data in the Default Item Name Root field.
3
Select the rows that correspond to bits 0 and 1 in byte 0 (the first two rows).
4
Click the Define Item(s) button to open the Item Name Definition dialog box.
NOTE: An asterisk (*) in the Item Name field indicates that discrete items with the same root name are created.
5
Accept the default Item Name and click OK to create two discrete output items.
6
Click Apply to save the items and leave the page open.
7
Repeat these steps to create new output items.
Creating Numeric Output Items
To create output items for the STB NIC 2212, example, beginning with an output data word for the STB AVO 1250 module:
Step
Action
1
Select the Output tab.
NOTE: In this example, both the Offset/Device and Offset/Connection columns represent the byte address. The items you create will be 16-bit words comprising 2 bytes.
2
Enter AVO1250_CH1_out_data in the Default Item Name Root field.
3
Starting at the next available whole word, select two rows (rows 2 and 3).
4
Click the Define Item(s) button to open the Item Name Definition dialog box.
5
Click OK to create the output word.
6
Click Apply to save the items and leave the page open.
7
Repeat these steps to create a new word for the AVO 1250 channel 2 output data (at bytes 4 and 5).
8
Click OK to close the Items window.
9
Select File → Save to save your edits.