I. Hanakawa,
It is possible to connect the ER8 to your PCI-6229, but unfortunately
there is no way to do this with the ER16 relay module due to the higher
channel count. Here is a link to a knolwedgebase describing what
accessories are needed and how to create the connections:
KnowledgeBase 3ECDRBPK: Using M Series Boards With ER-8/16 Relay Modules
You will need to route your signals from the ER8 to your DAQ card
through an SC 2050 connector block. The following document
contains diagrams of cabling configurations, including those for use
with the ER-9 Relay Module:
Cable Adapters for Signal Conditioning
By sure to reference your ER-8 module User's Guide in order to
configure the power source for your relays (internal or external).
I hope this helps!
Travis Gorkin
Applicaitons Engineering
National Instruments
www.ni.com/support