Line 6 Helix Rack: MIDI CC, NRPN and OSC map¶
The Line 6 Helix Rack as named OSC addresses — 35 CC — ready to use from Claude (MCP), SuperCollider, Sonic Pi, TouchDesigner or any OSC app via osc-bridge.
| Device | Line 6 Helix Rack |
|---|---|
| Vendor | Line 6 |
| OSC prefix | /helix_rack |
| Source | 📦 Derived from MIDI Guide (community CC/NRPN data) |
| Firmware | unknown |
| Revision | per pencilresearch canonical CSV |
| Upstream | pencilresearch |
| Data licence | CC-BY-SA-4.0 — MIDI Guide (https://midi.guide) by Pencil Research and contributors |
| Driver file | devices/line-6/helix_rack.pencilresearch.fw-unknown.json |
Not tested on the device yet
This driver comes from documentation or community data and has not been checked on real hardware. If you own one, a quick test and a pull request promoting it helps everyone — see CONTRIBUTING.
How do you control it?¶
Find the MIDI ports, then start the bridge with this driver:
osc-bridge detect # prints the ready-to-run line for what is plugged in
osc-bridge run --device devices/line-6/helix_rack.pencilresearch.fw-unknown.json --out-port <N> --in-port <M>
Then send OSC to 127.0.0.1:7777, for example:
From Claude or any MCP client, the osc-bridge mcp server exposes this driver as helix_rack: ask “what can the Line 6 Helix Rack do?” and it reads this map with list_routes. See the MCP guide.
MIDI CC and NRPN parameters (35)¶
| OSC address | CC | NRPN (MSB/LSB) | Range | Nature | Section |
|---|---|---|---|---|---|
/helix_rack/banks_and_presets/bank_msb |
0 | 0–7 | continuous | Banks and presets | |
/helix_rack/banks_and_presets/bank_lsb |
32 | 0–7 | continuous | Banks and presets | |
/helix_rack/banks_and_presets/snapshot_select |
69 | 0–127 | continuous | Banks and presets | |
/helix_rack/banks_and_presets/mode_switch |
71 | 0–127 | continuous | Banks and presets | |
/helix_rack/banks_and_presets/preset_previous_next |
72 | 0–127 | continuous | Banks and presets | |
/helix_rack/banks_and_presets/page_left_right |
81 | 0–127 | continuous | Banks and presets | |
/helix_rack/expression_pedal/1 |
1 | 0–127 | continuous | Expression pedal | |
/helix_rack/expression_pedal/2 |
2 | 0–127 | continuous | Expression pedal | |
/helix_rack/expression_pedal/3 |
3 | 0–127 | continuous | Expression pedal | |
/helix_rack/expression_pedal/exp_toe_switch |
59 | 0–127 | continuous | Expression pedal | |
/helix_rack/footswitch_control/footswitch_1 |
49 | 0–127 | continuous | Footswitch control | |
/helix_rack/footswitches/footswitch_2 |
50 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_3 |
51 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_4 |
52 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_5 |
53 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_7 |
54 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_8 |
55 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_9 |
56 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_10 |
57 | 0–127 | continuous | Footswitches | |
/helix_rack/footswitches/footswitch_11 |
58 | 0–127 | continuous | Footswitches | |
/helix_rack/looper/record_overdub |
60 | 0–127 | continuous | Looper | |
/helix_rack/looper/play_stop |
61 | 0–127 | continuous | Looper | |
/helix_rack/looper/play_once |
62 | 0–127 | continuous | Looper | |
/helix_rack/looper/undo_redo |
63 | 0–127 | continuous | Looper | |
/helix_rack/looper/forward_reverse |
65 | 0–127 | continuous | Looper | |
/helix_rack/looper/full_half_speed |
66 | 0–127 | continuous | Looper | |
/helix_rack/looper/block_on_off |
67 | 0–127 | continuous | Looper | |
/helix_rack/parameter_control/tap_tempo |
64 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_1 |
75 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_2 |
76 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_3 |
77 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_4 |
78 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_5 |
79 | 0–127 | continuous | Parameter control | |
/helix_rack/parameter_control/parameter_knob_6 |
80 | 0–127 | continuous | Parameter control | |
/helix_rack/tuner/tuner |
68 | 0–127 | continuous | Tuner |
Performance MIDI¶
Notes, pitch bend and any CC are also available: /helix_rack/note/on <note> <velocity>, /helix_rack/cc/<number> <value>, /helix_rack/pitchbend <0-16383>, /helix_rack/program_change <n>.
Limitations¶
CC/NRPN only. SysEx (preset management, display control, bulk dump/load, vendor-proprietary opcodes) is NOT covered by pencilresearch. To extend this device with SysEx, sniff the vendor editor, add `sysex.header/footer` + `commands` blocks, and use `update_device.md` PR template.