Remapping Variables in an I/O Device

Some PLCs allow you to remap (or copy) an I/O device variable to another register address. Citect SCADA allows you to remap to:

To remap a variable in your PLC, you need to design (or modify) the logic in the PLC to associate both addresses. Citect SCADA can then read or write the variable to and from the remapped address instead of the physical address.

You can also reassign one type of variable (for example, an integer) to another type of variable (for example, a digital variable).

To remap in Citect SCADA, first create the variables in your project as you would normally. Then you can set up the remapping, specifying that any variable with an address in the desired range will be remapped. The I/O server will redirect the addresses at runtime as per the remapping instruction.

Note: Not every PLC and/or Citect SCADA driver supports remapping. It is not recommend unless necessary. Contact Technical Support if you need to evaluate whether the PLC and/or driver support remapping.

Note: To determine if the device supports remapped reads or writes, see the I/O Device Data Type help.

Property	Description
Citect SCADA variable	The first remapped (Citect SCADA) variable defined in the variable tags database (using the Tags dialog box); for example: `Motor_1_Run.` (79 characters maximum). Alternatively, use the direct <Unit Name>\|<Address>\| format (using values specific to your I/O device); for example: IODev\|X1\|. The address entered here is remapped. At runtime the I/O server will read/write data through the physical address instead.
Length	The number of remapped variables. Citect SCADA reads enough physical variables to remap this number of variables (10 characters maximum). The length needs to be less than the maximum request lengthThe maximum number of data bits that can be read from the I/O device in a single request. For example, if the maximum request length is 2048 bits, the maximum number of integers that can be read is: 2048/16 = 128. of the protocolMessaging format consisting of a set of messages and guidelines used for communication between the Citect SCADA server and an I/O device. The communication protocol determines how Citect SCADA and the I/O device communicate; the type of data to exchange; rules governing communication initiation and termination; and error detection.. The protocol overview displays the maximum request length of the protocol.
Physical Variable	The first physical variable in the PLC, for example: ReMapIntV7. (79 characters maximum). This variable does not need to be defined in the variable tags database. You can use the <Unit Name>\|<Address>\| format (using values specific to your I/O Device). For example, IODev\|V7\|.
Remap Read	Determines whether to perform the remapping for reads. Set to TRUE or FALSE. FALSE - Read normal (not remapped) variables. The actual address of the Citect SCADA variables will be read directly from the I/O Device, instead of through the Physical Variable. (Use this mode if your I/O Device does not support remap reads.) TRUE - Read remapped variables (through the physical variable).
Remap Write	Determines whether to perform the remapping for writes. Set to TRUE or FALSE. FALSE - Write to normal (not remapped) variables. The actual address of the Citect SCADA variables will be written directly in the I/O Device, instead of through the physical variable. (You need to use this mode if your I/O Device does not support remap writes.) TRUE - Write to remapped variables (through the physical variable).
Comment	Any useful comment.

Property

Description

Citect SCADA variable

The first remapped (Citect SCADA) variable defined in the variable tags database (using the Tags dialog box); for example: Motor_1_Run.

(79 characters maximum). Alternatively, use the direct <Unit Name>|<Address>| format (using values specific to your I/O device); for example: IODev|X1|.

The address entered here is remapped. At runtime the I/O server will read/write data through the physical address instead.

Length

The number of remapped variables. Citect SCADA reads enough physical variables to remap this number of variables (10 characters maximum).

The length needs to be less than the maximum request lengthThe maximum number of data bits that can be read from the I/O device in a single request. For example, if the maximum request length is 2048 bits, the maximum number of integers that can be read is: 2048/16 = 128. of the protocolMessaging format consisting of a set of messages and guidelines used for communication between the Citect SCADA server and an I/O device. The communication protocol determines how Citect SCADA and the I/O device communicate; the type of data to exchange; rules governing communication initiation and termination; and error detection.. The protocol overview displays the maximum request length of the protocol.

Physical Variable

The first physical variable in the PLC, for example: ReMapIntV7. (79 characters maximum).

This variable does not need to be defined in the variable tags database. You can use the <Unit Name>|<Address>| format (using values specific to your I/O Device). For example, IODev|V7|.

Remap Read

Determines whether to perform the remapping for reads. Set to TRUE or FALSE.

FALSE - Read normal (not remapped) variables. The actual address of the Citect SCADA variables will be read directly from the I/O Device, instead of through the Physical Variable. (Use this mode if your I/O Device does not support remap reads.)

TRUE - Read remapped variables (through the physical variable).

Remap Write

Determines whether to perform the remapping for writes. Set to TRUE or FALSE.

FALSE - Write to normal (not remapped) variables. The actual address of the Citect SCADA variables will be written directly in the I/O Device, instead of through the physical variable. (You need to use this mode if your I/O Device does not support remap writes.)

TRUE - Write to remapped variables (through the physical variable).

Comment

Any useful comment.