forked from sinara-hw/assembly
47 lines
2.8 KiB
Markdown
47 lines
2.8 KiB
Markdown
|
# DRTIO
|
||
|
|
|
||
|
|
This page intends to help users solve problems with their DRTIO systems.
|
||
|
|
|
||
|
|
## Description (from user experience)
|
||
|
|
|
||
|
|
[Distributed Real Time Input/Output](https://m-labs.hk/artiq/manual/drtio.html) - allows almost seamlessly connecting several satellites to one master crate,
|
||
|
|
so that all the crates can be controlled as one whole crate. The connection between the crates is done either by passive copper
|
||
|
|
direct attach cables (suitable for one-crate setups) or optical fibers SFP+ adapters (suitable for multiple crates that
|
||
|
|
can be distributed up to [several kilometers](https://github.com/m-labs/artiq/issues/2022)). The DRTIO protocol is not
|
||
|
|
compatible with Ethernet, and moreover, satellites do not have any network access and can be controlled only by master.
|
||
|
|
However, both star (2 levels) and tree topologies are supported as well,
|
||
|
|
with default one being the star (one master and up to 3-4 directly connected satellites), and if any chaining is needed, the
|
||
|
|
routing table setup is needed.
|
||
|
|
To switch between satellite/master/standalone variants you just need to flash appropriate firmware, and set the respective `base`
|
||
|
|
field in the JSON description.
|
||
|
|
|
||
|
|
The master will attempt to connect the satellite whenever it sees that there are SFPs plugged in. For this purpose,
|
||
|
|
it will _ping_ the satellite until it establishes the connection. This connection process can be observed from the logs:
|
||
|
|
```rust
|
||
|
|
// successful connection
|
||
|
|
[ 5385.011286s] INFO(runtime::rtio_mgt::drtio): [LINK#1] link RX became up, pinging
|
||
|
|
[ 5390.219274s] INFO(runtime::rtio_mgt::drtio): [LINK#1] remote replied after 27 packets
|
||
|
|
[ 5390.257152s] INFO(runtime::rtio_mgt::drtio): [LINK#1] link initialization completed
|
||
|
|
[ 5390.264854s] INFO(runtime::rtio_mgt::drtio): [DEST#2] destination is up
|
||
|
|
[ 5390.271567s] INFO(runtime::rtio_mgt::drtio): [DEST#2] buffer space is 128
|
||
|
|
|
||
|
|
// not successful connection:
|
||
|
|
[ 95.269811s] INFO(runtime::rtio_mgt::drtio): [LINK#1] link RX became up, pinging
|
||
|
|
[ 115.076772s] ERROR(runtime::rtio_mgt::drtio): [LINK#1] ping failed
|
||
|
|
```
|
||
|
|
|
||
|
|
During the connection, the clock signal is being distributed, effectively making the clocks across crates to be synchronized.
|
||
|
|
|
||
|
|
|
||
|
|
## Common problems
|
||
|
|
|
||
|
|
### Master and satellite do not connect with each other
|
||
|
|
|
||
|
|
* Shady cables and SFP adapters are often the cause, use the adapters from reputable sources, or better, use the one we ship.
|
||
|
|
You may also contact our helpdesk to get help in choosing the right adapters if needed.
|
||
|
|
* The adapter is not pushed until the end. You shouldn't be able to pull out the adapters without pulling the petals/handles.
|
||
|
|
* The fiber is not properly connected - you shouldn't be able to pull it out without squeezing the handle. Also the optics
|
||
|
|
may be dirty or damaged.
|
||
|
|
* Wrong setups - master to master, standalone to standalone. Messing up with SFP ports generally makes it unusable,
|
||
|
|
but the connection should be established in most cases.
|