Parameter

Description

Symbol

Process variable that is mapped to the fieldbus variable.

Default: ???

Status/Control

Diagnostic information provided to the application.

Allows to use the dropdown menu to select the desired setting, if active.

Hint: Slave status variables can only be used, if the option Manage diagnostic info for slaves in the Master/port dialog is active.

Settings:

• Error report
  The variable is set to an error value when the last unsuccessful exchange is performed on the request. It is reset to 0 on the next successful exchange.
• Error report (Set only)
  Same as upper, but the variable is not reset by the MODBUS stack. The application is in charge of resetting the variable.
• On-going request
  The variable is set to 1 when the request is sent to the slave and reset to 0 after either an answer from the slave or a timeout.
• Success counter
  The variable is increased each time the request is exchanged successfully.
• Fail counter
  The variable is increased each time the exchange of the request leads to an error.
• Retry counter
  The variable is set to 0 on the first trial and increased each time the request is retried.
• Command (one shot)
  The request is sent only once when the mapped command variable becomes TRUE (or not zero). The variable is reset to 0 after the exchange.
• Command (enable)
  The request is sent continuously as long as the mapped command variable is TRUE (or not zero).
• Reset counters
  The request counters are reset to 0 when the variable becomes TRUE (or not zero), and the command variable is then reset to 0.
• Slave: last error
  The variable contains the error code of the last error detected on this slave.
• Slave: last error date stamp
  The variable contains the date stamp of the last error detected on this slave.
• Slave: last error time stamp
  The variable contains the time stamp of the last error detected on this slave.
• Slave: last reset date stamp
  The variable contains the date stamp of the last "reset" action performed on slave counters.
• Slave: last reset time stamp
  The variable contains the time stamp of the last "reset" action performed on slave counters.
• Slave: transaction counter
  The variable is increased on any new exchange performed with this slave, whatever the exchange is successful or faulty.
• Slave: failed transaction counter
  This variable is increased on any new faulty exchange with this slave.
• Slave: reset counters
  The slave counters are reset to 0 when the variable becomes TRUE (or not zero), and the command variable is then reset to 0.

Default: inactive

Data exchange

Variable is used for process data exchange.

Default: active

Offset:

Position of the data inside the MODBUS map.

Default: 0

Mask:

A hexadeciamal Mask (e.g. 0001) for exchanging boolean variables through MODBUS words.

Default: FFFF

Storage:

For exchanging 32 bit variables (DINT, REAL...), you can select to map the variable on two consecutive words.

• STRING variables are supported only if a "string" data format is specified.
• 64 bit variable (LINT and LREAL) cannot be extracted directly without lost of accuracy or data.

Settings:

• Default
• DWORD (High - Low)
• DWORD (Low - High)
• STRING(6)
• STRING(8)
• STRING(10) - STRING(240)

Hint: The STRING length has even numbers only.

Default: Default

Range

Min/Max value of the process variable in the application.

The Range and Signal settings allow to decode the Slave values for the Master without any code.

Example: If you have a Slave which is coding a 0 to 10V measurement on 10 Bits, the value range reaches from 0 to 2047. The Master side is receiving a value from 0 to 2047 instead of 0 to 10V. Using this option the Master decodes the value from the Slave automatically and changes the Bit value 1024 to the voltage measurement 5V.

Min:

Defines the minimal value of the process variable.

Default: empty

Max:

Defines the maximum value of the process variable.

Default: empty

Signal

Min/Max value sent or received in the MODBUS frame.

The Range and Signal settings allow to decode the Slave values for the Master without any code.

Min:

Defines the minimum range value.

Default: empty

Max:

Defines the maximum range value.

Default: empty

Option

Description

OK

Applies settings and closes the dialog.

Cancel

Discards all changes and closes the dialog.

Configuration

IEC 61131-3 Automation platform > Drivers - Fieldbus configuration > MODBUS Master > Variables > Configuration