# Command byte when a module sends this memory dump

**URL:** <https://forum.velbus.eu/t/command-byte-when-a-module-sends-this-memory-dump/10044>\
**Category:** For developers\
**Created:** [November 17, 2014, 6:32pm UTC](https://forum.velbus.eu/t/command-byte-when-a-module-sends-this-memory-dump/10044 "2014-11-17T18:32:16Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Stis](https://forum.velbus.eu/letter_avatar_proxy/v4/letter/s/94ad74/32.png) [@Stis](https://forum.velbus.eu/u/Stis)\
**Post date:** [November 17, 2014, 6:32pm UTC](https://forum.velbus.eu/t/command-byte-when-a-module-sends-this-memory-dump/10044/1 "2014-11-17T18:32:16Z")

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to velbus,

there is a command for memory dump request H’CB’ but i don’t find the command byte when the module sends the memory dump. Is there a missing command? if so for what command byte have i to loof for?

thanks,

Stis

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<div class="post-metadata">

**Author:** ![VEL448](https://forum.velbus.eu/user_avatar/forum.velbus.eu/vel448/32/4186_2.png) [@VEL448](https://forum.velbus.eu/u/VEL448)\
**Post date:** [November 18, 2014, 7:24am UTC](https://forum.velbus.eu/t/command-byte-when-a-module-sends-this-memory-dump/10044/2 "2014-11-18T07:24:50Z")

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When you send a dump memory command you can expect a series of memory blocks. The memory dump command allows you to read the entire memory of a module without having to send a read memory command for every block.

\<- Memory dump  
-\> Memory block  
-\> Memory block  
-\> Memory block  
…

vs

\<- Read memory block  
-\> Memory block  
\<- Read memory block  
-\> Memory block  
…

Some older modules don’t support the memory dump command