The I/O Scanning Tab
Original instructions
Introduction
Use the I/O Scanner to scan I/O modules to get inputs and set outputs.
I/O Scanning Tab
The following procedure shows how to access the BMX NOE I/O Scanning tab from the index page:
Step
Action
1
Open your application using the BMX NOE 01x0 in Control Expert.
2
In the Project Browser, locate the Communication → Networks sub-directory.
3
Click the Ethernet module (BMX NOE 01x0 in our example) to open the Ethernet module configuration screen.
4
In the Module Utilities field, select Yes in the IO Scanning menu.
5
Select the I/O Scanning tab to open the I/O scanning configuration screen:
6
Enter the parameter settings under each of the column headings for one line of the I/O Scanner Configuration. Refer to I/O Scanning Parameters (below) to see the settings used for this example.
7
Click the validate check box in the upper tool bar to confirm the I/O scanning parameter settings.
I/O Scanning Parameters above Table
Master %MW zone parameters:
Parameter
Field
Description
Read Ref.
A pair of data boxes — From and to
The values in these boxes define the range of destination address values in the CPU for the data read from each device. The addresses you enter here are displayed in the RD Master Object column of the dialog. In the example above, the Read Ref. values range from 0 to 599. Notice that these values are displayed as %MW0, %MW599, etc. in the Master Object column.
Write Ref.
A pair of data boxes — From and to
The values in these boxes define the range of source address values in the CPU. The address you enter here is displayed in the WR Master Object column. In the example above, values starting at %MW2000 are shown in the WR Master Object column.
The Repetitive rate step parameter:
Parameter
Field
Description
Repetitive rate step
data box
The Repetitive rate step is set in multiples of 5 ms (the minimum) through 200 ms (the maximum).
The Repetitive rate (ms) column is where you enter a rate of time for how often you want the I/O scanner to send a query to the device after the rate has timed out.
NOTE: The Repetitive rate (ms) of the I/O scanner table is a multiple of the rate displayed in the Repetitive rate step box. The real repetitive rate being executed by the I/O scanner service is shown in the Repetitive rate (ms) column.
NOTE: An entry in the Repetitive rate (ms) column is rounded up to the next multiple that was entered in the Repetitive rate step if the entry is not a multiple of the Repetitive rate step.
For example, if the entry in the Repetitive rate step is 5 and you enter a 7 in the Repetitive rate (ms) column, the 7 is rounded up to 10. If you change the Repetitive rate step to 6 and enter a 7 in the Repetitive rate (ms) column, the 7 is rounded up to 12.
I/O Scanning Table Parameters
The I/O Scanning table configuration parameters are:
Parameter
Description
Example
Entry #
This is the first column; it has no name.
Valid range: 1 ... 64
Each entry represents an I/O Scanning exchange on the network.
IP address
This is the IP address of the scanned Ethernet slave device.
192.168.1.100
Device Name
To configure a device (Advantys island, DTM or PRA), click the ... button to open the Property box to start the device configuration software.
For an introduction to this procedure for Advantys, go to Advantys configuration.
For an introduction to this procedure for DTMs, go to PRM Master DTM configuration.
For an introduction to this procedure for PRA, go to BMX PRA 0100 configuration.
NOTE: While the Property box is open, I/O scanning cannot be edited.
MySTB1, Master_PRM_DTM_10, PRA1
Unit ID
This field associates the slave address of the device connected to an Ethernet/Modbus gateway with the IP address of that gateway:
  • value range: 1 to 255
  • default value: 255
When using a bridge, enter the bridge index (1 to 255) in this field.
255
Slave Syntax
Use this drop-down menu to pick the way RD Ref Slave and WR Ref Slave values are displayed. The 4 choices are (with an example):
  • Index: 100
  • Modbus: 400101
  • IEC 0: %MW100
  • IEC 1: %MW101
Index (default value)
Health Timeout (ms)
This field sets the maximum interval between the responses from a remote device:
  • range: 0ms to 50 seconds
  • interval: 1ms
After this time period expires, the received data is invalid.
The health timeout must longer than the repetitive rate. For an NOE Ethernet module, it also must be longer than the CPU scan time.
1500ms
Repetitive rate (ms)
The rate at which data will be scanned, from 0...60000 in multiples of the Repetitive rate step.
60ms
RD Master Object*
Destination address in the master PLC where, from each device, newly read information is stored.
This parameter cannot be accessed. It is calculated automatically as the sum of:
  • The From address (beginning) of Read ref. (in the zone above the table)
  • The RD length value (in the table below)
%mw10
RD Ref Slave**
Source address index in the slave/remote device
The format of this value depends on the Slave Syntax:
  • Index: 5
  • Modbus: 400006
  • IEC 0: %MW5
  • IEC 1: %MW6
RD length
Number of words to read
10
Last value (input)
This field configures the behavior of inputs in the event of an access error in relation to the remote device (for example: inoperative network or device power supply, etc.):
  • Set to 0: fall back to 0
  • Hold last: maintain last value
Hold last
WR Master Object*
Source address of the master PLC whose data is being written into the slave/remote device.
This parameter cannot be accessed. It is calculated automatically as the sum of:
  • The From address (beginning) of Write ref. (in the zone above the table)
  • The WR length value (in the table below)
Write operations are always performed at the word level.
%mw20
WR Ref Slave**
The address of the first word written into the slave/remote device.
The format of this value depends on the Slave Syntax:
  • Index: 1
  • Modbus: 400002
  • IEC 0: %MW1
  • IEC 1: %MW2
WR length
Number of words to be written
10
Gateway/Bridge Device
To allow slower TCP/IP network devices (ex: gateways and bridge) to be compatible with the I/O Scanner:
  • Select the check box to enable this feature. Defines a new bit, and sets it to high (1).
  • Deselect the check box to disable this feature (default). Defines a new bit, and sets it to zero (0).
Values:
  • Disable = deselected check box
  • Enable = selected check box
Description
Additional information
*Master refers to the client PLC that makes the request.
**Slave refers to the server from which data is read or to which data is written.
NOTE: For more information about the I/O Scanning table, refer to the Contextual Menu for Copy/Cut/Paste topic.
NOTE: For more information about the I/O Scanning table, refer to the I/O Scanning with Multiple Lines topic.