KATCP

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KATCP stands for Karoo Array Telescope Control Protocol. It is a syntax specification for controlling devices over a TCP or RS232 link. It is the preferred remote command and control interface for ROACH, and all ROACH boards ship with a daemonized KATCP server.

This page serves as a Getting started guide for users. Software developers trying to implement a KATCP client or server should consult Memo #32 for detailed information about the KATCP protocol.

Contents

Connecting

Open a telnet connection to your ROACH board on port 7147. Multiple connections are supported, but you will need to manage this yourself (ie, if two connections try to read/write to a register at the same time, the behaviour is undefined).

Command syntax

All commands are prefixed with a question mark (?) and suffixed with a carriage-return or line-feed. To get a list of available commands, type

?help

and press enter.

Every command will produce a response.

All responses are prefixed with an exclamation mark (!) followed by the command name and a response of the form ok, invalid or fail. For multi-line responses, each line will start with a hash (#), and the final line will consist an exclamation mark (!) followed by the number of lines you should have received.

These characters (?, #, !) are all reserved characters. If you want to use one of them, you must escape it with a preceding backslash (\). See section 2.1: Message grammar of the KATCP memo for details.

Arguments are separated by spaces. While you can put escaped spaces or tabs in an argument, we recommend that you avoid doing so because it makes parsing the results more difficult. Try to use underscores instead.

Clients and servers

Generic KATCP Client/Server Libraries:

  • Python library - Karoo Array Telescope Communication Protocol library Python reference implementation
  • C Library
  • Ruby library - Ruby/KATCP is a Ruby extension for communicating via KATCP
  • No Java library available yet.

ROACH-specific Clients:

There is a ROACH-specific wrapper in the Python client package.

ROACH-specific commands

In addition to the core KATCP commands (eg, help, restart, sensor-list, etc.), there are some new commands specifically for interfacing with FPGAs.

What follows is a list of the basic ones, along with their usage. This list will probably not be kept up-to-date, so for the latest info, you'll want to call help on any particular function from within a Python shell.

wordwrite

Writes data words to a named register.

write

Writes arbitrary data lengths to a named register. Only useful once the FPGA has been programmed.

?write <register name> <offset> <data>

Where:

  • register name is a string value as listed in listdev.
  • offset is an integer specifying the byte offset from where you'd like to start writing.
  • data is the raw binary data stream to write to that location (big endian).

wordread

Reads data words from a named register.

indexwrite

Writes arbitrary data lengths to a numbered register. This was important on clients with low-power CPUs (BEE2) where the overhead to match strings for register names caused significant bottlenecks. Registers could thus be indexed using an integer lookup. ROACH's PPC440 is significantly faster and does not suffer from this limitation. It is here for legacy purposes, but has not been tested with ROACH.

indexread

Reads arbitrary data lengths from a numbered register. This was important on slower clients (BEE2) where the overhead to match strings for register names caused significant bottlenecks. Registers could thus be indexed using an integer lookup. ROACH's PPC440 is significantly faster and does not suffer from this limitation. It is here for legacy purposes, but has not been tested with ROACH.

read

Reads arbitrary data lengths from a named register. Only useful once the FPGA has been programmed. Data is returned in big-endian format.

?read <register name> <offset> <size> 

Where:

  • register name is a string value as listed in listdev.
  • size is an integer in bytes (keep multiple of four) of how much data you'd like to retrieve from this register.
  • offset is an integer specifying the byte offset from where you'd like to start reading.

listdev

Displays available device registers. Only useful if the FPGA is programmed. Newer tcpborphserver2 versions accept an optional size argument which causes device sizes to be given as well.

?listdev [size]

listcmd

Displays available Linux shell commands. Takes no arguments. This is useful for remotely executing a custom script. There will be a command available in a future release for executing these commands (execcmd).

?listcmd

listbof

Displays available BORPH bitstreams in /boffiles. Takes no arguments. When running progdev, you need to supply the string argument exactly as printed here.

?listbof

status

Displays image status information. Takes no arguments.

If the FPGA is programmed, you'll receive a string with the path to the hardware registers, eg !status ok /proc/335/hw/ioreg.

If the FPGA is not programmed, you'll receive a status error.

?status

progdev

Programs the FPGA with a BORPH bitstream. See the listbof command for available bitstreams.

?progdev <my_borph_file.bof>

sensor-list

Lists sensors. The intention is to add fan speeds, voltage rails and temperatures here, however, this is not yet available. It will conform to generic KATCP sensor requirements when released.

tap-start

Program a 10GbE device and start the TAP driver.

?tap-start <device_name> <mac> <ip> <port>

Where:

  • device_name is a string: name of the device. (eg: gbe0)
  • mac is an integer: MAC address, 48 bits. (eg: 00:12:34:56:78:9a)
  • ip is an integer: IP address, 32 bits. (eg: 10.0.0.2)
  • port is an integer: port of fabric interface, 16 bits. (eg: 10000)

Note: The first two hex digits of the MAC address must be zeroes for it to be valid.

Note: Old versions only support one instance of tgtap. Please update your tcpborphserver if you need multiple instances.

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