User Program Size and Operands of the \ CM574-RS¶
Values
The following table shows the values set for program memory and operands in the CM574 target systems:
| Parameter / CPU | CM574-RS |
|---|---|
| User program (code), see note 1 | 256 kB |
| Number of POUs | 1024 kB |
| Number of tasks | 3 |
| Floating point processor, see note 2 | no |
| Global and local variables: VAR or VAR GLOBAL | 128 kB |
| Addressable flag area: VAR AT %Mx.y | 128 kB |
| Persistent area: VAR AT %Rx.y | 0 kB |
| Inputs %I, see note 4 | 4 kB |
| Outputs %Q, see note 4 | 4 kB |
| FLASH for user data | 2 x 64 kB = 128 kB |
Note 1
The user program is composed of:
- The compiled code of all POUs called in the program
- The initialization code for the variables
The configuration data are not included in the user program size.
Remark 2
All AC500 CPUs can perform floating point operations. For CPUs without floating point processor (like the CM574-RS), these operations are performed by an emulation library and are therefore slower. Emulation is faster for LREAL variables than for REAL variables. Thus, the use of LREAL variables is recommended.
Remark 3
The information shown in the message box exclusively contains the retain data of the RETAIN area, and not the variables of the addressable flag area %Mx.y. that are declared as VAR RETAIN.
The Communication Module CM574-RS is not equipped with a battery. For this reason, ALL operands are initialized once the control voltage is switched on.
In the Communication Module, data can be stored fail-safe in the Flash memory using the blocks FLASH_WRITE: FLASH_WRITE FLASH_WRITE and FLASH_READ: FLASH_READ FLASH_READ.
Remark 4
For the inputs and the outputs, the same rules apply as for the AC500-CPUs.
The following input and output assignment applies for the CM574-RS:
| CPU communication: | %IB0 .. | %IB999 | and %QB0 .. | %QB999 |
| Of this: Channel 1: | %IB0 | %IB499 | and %QB0 .. | %QB499 |
| Channel 2: | %IB500 .. | %IB999 | and %QB500 .. | %QB999 |
| COM1: | %IB1000 .. | %IB1999 | and %QB1000 .. | %QB1999 |
| COM2 : | %IB2000 .. | %IB2999 | and %QB2000 .. | %QB2999 |
Additional information can be found in the documentation “System Technology of the CPUs” in AC500 inputs, outputs and flags Inputs, Outputs and Flags.