======HOW TO UPGRADE CODE USING ZMODEM FILE TRANSFER (SDL2)======

**Symptoms:** How to upgrade code using Zmodem File Transfer (SDL2)  
  * Upgrade failed while using TRAM to do the software download.  

**Facts:** SuperStack II Remote Access System 1500  
  * Zmodem File Transfer  
  * SDL2  
  * Software Download  

**Fixes:** Use Zmodem file Transfer to complete the flash upgrade using Console connection. 

**1.** Use DB-9 to DB9 console cable and open Hyper Terminal select 38400, 8-n-1-hardware, 

**2.** Unplug the power on RAS1500 and then plug back the power. 

**3.** Press Esc keys 4 times when system starts. 

**4.** Type AT{H} to halt the boot sequence. 

**5.** Type AT{Z} to load the rasboot.dmf. Then the flash sequence will start. After boot flash complete, RAS will reboot, 

**6.** Use AT{Z} one more time to load ras1500.dmf. After running through this process, the flash upgrade will be completed. 

**7.** Use "show system" to confirm the system version.  
 




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  * Product(s):  SuperStack II Remote Access System 1500  
  * Sub Product(s): None set  



 --- //[[nce@itclatam.com|David Gonzalez]] 2021/04/09 11:27//