5: SPECIAL FUNCTIONS5-28 « FC4A MICRO SMART USER ’S MANUAL »Partial Program DownloadNormally, the CPU module has to be stopped before downloading a user program. The all-in-one 16- and 24-I/O type CPUmodules and all slim type CPU modules have run-time program download capabilities to download a user program con-taining small changes while the CPU is running in either 1:1 or 1:N computer link system. This function is particularlyuseful to make small modifications to the user program and to confirm the changes while the CPU is running. The all-in-one 10-I/O type CPU module does not have this functionality.Before performing the partial program download during operation, a user program has to be downloaded to the CPU mod-ule using the ordinary program download. Add or delete a part of the same user program, or make small changes to thesame user program using WindLDR, and download the modified user program while the CPU is running to confirm thechanges on-line.Another method of using this feature is: upload the user program from the CPU module to WindLDR, make changes, anddownload the modified user program using the partial program download while the CPU is running.In either case, do not convert the ladder diagram to mnemonic codes to generate a code file (Compile > Convert Ladder)before using the partial program download. WindLDR attaches a unique code to every code file when a ladder diagram isconverted to mnemonic codes. When the partial program download is attempted, WindLDR compares the unique codes ofthe user programs in the CPU module and currently opened on WindLDR. Only when WindLDR verifies that the uniquecodes are identical, the partial program download is enabled.Programming WindLDR1. Make changes to the user program using WindLDR. From the WindLDR menu bar, select Online > Partial ProgramDownload while the CPU module is running. The Partial Program Download dialog box appears.2. When using the MicroSmart in a 1:N computer link system, enter the device number of the CPU module in the DeviceNo. field. When using in a 1:1 computer link system, leave the default value in the Device No. field.3. Click the Download button to start the partial program download.4. When the partial program download is completed successfully, the above dialog box is displayed. Click the OK buttonto return to the WindLDR editing screen.Caution • The partial program download may cause unexpected operation of the MicroSmart. Before start-ing the partial program download, make sure of safety after understanding the function correctly.• If a user program syntax error or user program writing error occurs during the partial programdownload, the CPU module is stopped and all outputs are turned off, which may cause hazardsdepending on the application.
