Shared Memory Transfer

To transfer shared memory images between computers we can use the shmimTCP system. The goal is to make a copy or dummy shared memory on one machine that is then synchronized with the other machine over a dedicated ethernet connection.

Standard Use

For our standard use cases of transferring DM commands, the script dmdispbridge will setup the system for you. For instance, to send dmtweeter channel 03 commands from ICC to RTC, on ICC you can run

[xsup@exao3]$ dmdispbridge dm01disp03

The arguments can be any dm channel:

  • dm00dispXX for the woofer

  • dm01dispXX for the tweeter

  • dm61dispXX - dm66dispXX for GMT segments

To send dmncpc commands from RTC to ICC, on RTC you can run

[xsup@exao2]$ dmdispbridge dm02disp03

Manual Setup

More complicated uses require you to perform the steps yourself. This example shows how to send dmtweeter commands from ICC to RTC. Note that these are the steps performed by dmsispbridge for the same operation above, but this can be adapted to other devices/shmims as needed.

First on RTC:

tmux new -s sTCPrc-dm01disp06

Then in the tmux session:

$ shmimTCPreceive 8886

Second On ICC:

First create the shmim

cacao> mk2Dim "s>tf32>dm01disp06" 50 50
cacao> exit

Then make the connection (no tmux needed)

$ shmimTCPtransmit dm01disp06 8886

This example can be modified for other taskes (e.g. sending camtip to RTC)