I/O Scanner Offset Inconsistent Issue Across Different PLC Platforms

Issue
To explain users the offset inconsistent issue across the different PLC platforms when using Unity Pro software to configure I/O scanner table.

Product Line
EcoStruxure Control Expert (former Unity Pro), Modicon Quantum

Environment
140NOE77101

Resolution​​​​​
Due to the historic heritage reason, The Quantum product line including NOE77100/10/01/11, Quantum Copro 140CPU65150/60 do not support address %mw0 (or 400000). But Premium, M340 product line support address %MW0. So Unity Pro software allows users to put Read/Write index 0 for slave index in case the slave device is a Premium or M340 PRODUCTS.
The consequence is that using Unity Pro software, if the remote slave device is a Quantum product, the Read and Write index number will be increased by 1. If the remote slave device is Premium or M340 product, there is no offset by one.
Several I/O scanner configuration examples are used below for explaining this issue.

· Example 1: NOE77101 I/O scanner configuration table using Concept software

• • Master device: Quantum NOE77101

Slave device: Quantum NOE77111
Read/Write length: 1
Software: Concept V2.6

Offset issue: NO.
Read Ref Master (master address): 400001 (%mw1)
Read Ref Slave (slave address): 400001(%mw1)
Write Ref Master (master address): 400002 (%mw2)
Write Ref Slave (slave address): 400002(%mw2)


· Example 2: NOE77101 I/O scanner configuration table using Unity software

• • Master device: Quantum NOE77101

Slave device: Quantum NOE77111
Read/Write length: 1
Software: Unity V2.3

Offset issue: YES.
Read Master Object (master address): %mw1 (400001)
Read slave address: %mw1 (400001) Read slave Index: 0 the slave device is Quantum NOE, index number automatically increased by 1
Write Master Object (master address): %mw2 (400002)
Write slave address: %mw3 (400003) Write slave Index: 2 the slave device is Quantum NOE, index number automatically increased by 1

· Example 3: Quantum NOE77101 I/O scanner configuration table using Unity software

• • Master device: Quantum NOE77101
    Slave device: 140 CPU65150

Read/Write length: 1
Software: Unity V2.3

Offset issue: YES.
Read Master Object (master address): %mw1 (400001)
Read slave address: %mw1 (400001) Read slave Index: 0 the slave device is Quantum Copro, index number automatically increased by 1
Write Master Object (master address): %mw2 (400002)
Write slave address: %mw3 (400003) Write slave Index: 2 the slave device is Quantum Copro, index number automatically increased by 1

· Example 4: 140 CPU65150 I/O scanner configuration table using Unity software

• • Master device: Quantum 140 CPU65150

Slave device: Premium ETY 5103
Read/Write length: 1
Software: Unity V2.3

Offset issue: NO.
Read master Object (address): %mw1
Read slave address: %mw0 Read slave Index: 0 the slave device is Premium ETY, index number remains the same, no added offset by one.
Write master Object (address): %mw2
Write slave address: %mw2 Write slave Index: 2 the slave device is Premium ETY, index number remains the same, no added offset by one.


· Example 5: ETY5103 I/O scanner configuration table using Unity software

• • Master device: Premium TSX ETY5103

Slave device: NOE77101
Read/Write length: 1
Software: Unity V2.3

Offset issue: YES.
Read Master Object (master address): %mw1
Read slave address: %mw1 (400001) Read slave Index: 0 the slave device is Quantum NOE, index number automatically increased by 1
Write Master Object (master address): %mw2
Write slave address: %mw3 (400003) Write slave Index: 2 the slave device is Quantum NOE, index number automatically increased by 1


In summary, getting the offset by one or not, it all depends on the remote device if accepting address %mw0 or 400000. If yes, it has no offset issue. If no, user will see the index number automatically increased by 1.

Schneider Electric current has no plan to fix this issue because we don't want the large existing customers to change their application if they download the new firmware with the offset change.