---
name: "streamer"
section: "9"
platform: "linux"
package: "linuxcnc-uspace"
version: "1:2.9.4-2+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/streamer/9"
---

# streamer(9)

stream file data into HAL in real time

## NAME

streamer - stream file data into HAL in real time

## SYNOPSIS

**loadrt streamer depth**=*depth1\[,depth2...\]* **cfg**=*string1\[,string2...\]*

## DESCRIPTION

**streamer** and **[halstreamer(1)](/halstreamer/1.md)** are used together to stream data from a file into the HAL in real time. **streamer** is a realtime HAL component that exports HAL pins and creates a FIFO in shared memory. **hal\_streamer** is a non-realtime program that copies data from stdin into the FIFO, so that **streamer** can write it to the HAL pins.

## OPTIONS

**depth**=*depth1\[,depth2...\]*

Sets the depth of the FIFO that the realtime **streamer** creates to receive data from the non-realtime **hal-streamer**. Multiple values of *depth* (separated by commas) can be specified if you need more than one FIFO (for example if you want to stream data to two different realtime threads).

**cfg**=*string1\[,string2...\]*

Defines the set of HAL pins that **streamer** exports and later writes data to. One *string* must be supplied for each FIFO, separated by commas. **streamer** exports one pin for each character in *string*. Legal characters are:

• **F**, **f** (float pin)

• **B**, **b** (bit pin)

• **S**, **s** (s32 pin)

• **U**, **u** (u32 pin)

## FUNCTIONS

**streamer**.*N*

One function is created per FIFO, numbered from zero.

## PINS

**streamer**.*N*.**pin**.*M* output

Data from column *M* of the data in FIFO *N* appears on this pin. The pin type depends on the config string.

**streamer**.*N*.**curr-depth** s32 output

Current number of samples in the FIFO. When this reaches zero, new data will no longer be written to the pins.

**streamer**.*N*.**empty** bit output

TRUE when the FIFO *N* is empty, FALSE when valid data is available.

**streamer**.*N*.**enable** bit input

When TRUE, data from FIFO *N* is written to the HAL pins. When false, no data is transferred. Defaults to TRUE.

**streamer**.*N*.**underruns** s32 read/write

The number of times that **sampler** has tried to write data to the HAL pins but found no fresh data in the FIFO. It increments whenever **empty** is true, and can be reset by the **setp** command.

**streamer**.*N*.\*clock bit input

Clock for data as specified by the clock-mode pin

**streamer**.*N*.\*clock-mode s32 input

Defines behavior of clock pin:

• 0 (**default**) free run at every iteration

• 1 clock on falling edge of clock pin

• 2 clock on rising edge of clock pin

• 3 clock on any edge of clock pin

## SEE ALSO

[**halstreamer**(1)](/halstreamer/1.md), [**sampler**(9)](/sampler/9.md), [**halsampler**(1)](/halsampler/1.md)

## BUGS

Should an enable HAL pin be added, to allow streaming to be turned on and off?

## AUTHOR

Original version by John Kasunich, as part of the LinuxCNC project. Improvements by several other members of the LinuxCNC development team.

## REPORTING BUGS

Report bugs to jmkasunich AT users DOT sourceforge DOT net

## COPYRIGHT

Copyright © 2006 John Kasunich. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.