CXv4 beginer's guide - femanov/pycx4 GitHub Wiki
It's assumed that you know how to work in a linux environment. CX is a control system software based on standard three layer model. The model includes hardware/drivers layer, server layer and user applications layer. CX server is using channels (input/output units) in order to provide program-to-program communications in a control system (programs here are drivers, GUIs, services, etc). Channel is a piece of server's memory that you can read, write, and have events that it's updated. You need to get working server and a simple client to see how this works. Let's consider how to make them to work.
First you need to get CX distribution. Currently there is no repository with CX, you can search for it yourself in following places:
oper@linac3:work - current place where control room's copy is.
oper@linac3:DISTR - some archives... w.... - contains work (where CX is located).
Or just contact Dmitry Bolkhovitianov, and ask him where to get CX and why no public repository. Don't forget to eat his brain.
So you get a CX copy? It's usually located in $HOME/work like in bolkhov's machine or archive. But I have my own work and do not want to install any distributions to work...Ok. just create any dir you want and put there following dirs from bolkhov's work:
- 4cx - CXv4 it self, you going to work with
- hw4cx - drivers, basic screens
- sw4cx - control rooms software
- cx - CXv2, some parts of it in use yet. May be needed to access old servers
- v2hw - CXv2 drivers,
- qult - CXv2 control room software
- uspci - driver for PCI
- bpms - bpms by Rogovsky
Following software is required to build CX: motif, motif-devel, libXpm libXpm-devel, qt-devel, m4, ... Install it if needed.
Now you need to build CX... there is some docs: 4cx/src/doc/ and cx/src/doc/short.html for CXv2.
But it will take some time to cut through...Just take this scripts and edit its.
make_all.sh - to make CX, clean_all.sh - to clean it and makelog.sh - to make build log for
Dmitry Bolkhovitianov if build unsuccessful.
Put this scripts to you CX dir, change CXDIR variable inside make_all.sh, clean_all.sh and build CX.
After successful build:
- all libraries in 4cx/src/lib ready and you can build you C apps for cx with them,
- CXv4 server ready to work, 4cx/src/programs/server/cxsd - is a deamon to run,
- you can use cdaclient for some command line tests 4cx/src/programs/utils/cdaclient
Let's consider how to config and run CX server. To ran a server you need two config files - xxx.devlist and xxx.conf. conf-file is a general server config. Use the one from examples and edit a path to drives inside. devlist - contains a description of server's channels. In CXv4 channels are typed and can have int number of elements. the following types are supported:
| type | code |
|---|---|
| int8 | b |
| int16 | h |
| int32 | i |
| int64 | q |
| float | s |
| double | d |
| text | t |
| utext | u |
uints are also supported
channels can be read and write kind and defined by groups (devices). It's fully considered in bolkhov's docs 4cx/src/doc/cxsd-devlist.ru.html to define a device: you need to write a line to devlist file:
dev NAME noop 100r200i
This means yo defines a device with name "NAME", driver "noop", device has 100 read-kind channels of 200 int32 values each. When you start the server it alloc a memory for channels - 100 * 200 * 4b = 80000b for this line. Client that listen to all this channels will also alloc this amount memory. Don't write too big numbers to channel config - it can make you out of memory.
Read and write kind if channels - are not really read and write for user. It's considered like read and write for driver/hardware or for simulation mode of server.
In simulation mode server will continuously change value of read channels and will not touch write Driver noop means postbox-driver, it just keeps what you put in.
A name for defined above channels are NAME. It's channels named NAME.0 ... NAME.99, names are case insensitive. It's possible to add a name and units for some channel in devlist file:
cpoint linmag.lens10.Iset name.0 units:A
The line above will create alternative name "linmag.lens10.Iset" for "name.0".
There are some test devlists and scripts for running servers here and look server's help with "cxsd -h" command.
Full manual on naming can be found at 4cx/src/doc/misc_notes.html. Small summary of it: Full channel names looks like PROTOCOL::SERVER:N.CHANNEL_NAME@OPTIONS Protocols: CX, V2CX, INSRV (internal for driver-server), LOCAL (internal for monolitic app), VCAS (partly implemented), EPICS (not implemented). No "PROTOCOL::" = "CX::". SERVER:0 - is a network name or ip of you machine and server number. If you run server locally use "localhost", server number you provided in a server-starting command line. Try "cdaclient localhost:1.name.0" to read first channel of server started with runserver_1.sh from here