Summary

BSS Soundweb London devices support third-party control via the London Direct Inject protocol over RS-232 and 100Mb/s Ethernet (TCP/IP port 1023). Two-way communication allows setting or requesting any parameter or meter value. Devices are always listening; no enable step required. Serial acknowledgement uses 0x06 (valid) / 0x15 (checksum error). TCP uses native reliability — no acknowledgement.

Transport

protocols:
  - tcp
  - serial
addressing:
  port: 1023  # TCP port Soundweb London listens on
serial:
  # UNRESOLVED: baud rate not stated in source; configured via Audio Architect Properties window
  # UNRESOLVED: data_bits, parity, stop_bits not stated in source
  # Note: 9-pin D-type port; only pins 2, 3, 5 used
auth:
  type: none  # inferred: no auth procedure in source

Traits

# Inferred from protocol capabilities:
- powerable      # UNRESOLVED: power commands not explicitly documented in this source
- routable        # UNRESOLVED: routing commands not explicitly documented in this source
- queryable       # SUBSCRIBE/GET pattern present - parameter values can be requested
- levelable       # SET PERCENT, BUMP PERCENT present - gain/volume control possible

Actions

# Message type opcodes from source:
- id: set_parameter
  label: Set Parameter (Raw)
  kind: action
  params:
    - name: node_address
      type: integer
      description: "2-byte node address (0x0001-0xFFFE)"
    - name: virtual_device
      type: integer
      description: "1-byte virtual device (Audio=0x03, Logic=0x02)"
    - name: object_id
      type: integer
      description: "3-byte object ID"
    - name: parameter_id
      type: integer
      description: "2-byte parameter ID"
    - name: value
      type: integer
      description: "4-byte signed raw value"

- id: subscribe
  label: Subscribe to Parameter
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer

- id: unsubscribe
  label: Unsubscribe from Parameter
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer

- id: set_percent
  label: Set Parameter (Percent)
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer
    - name: percent
      type: number
      description: "0-100%"

- id: subscribe_percent
  label: Subscribe to Parameter (Percent)
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer

- id: unsubscribe_percent
  label: Unsubscribe from Parameter (Percent)
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer

- id: bump_percent
  label: Bump Parameter Up/Down (Percent)
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer
    - name: delta_percent
      type: number
      description: "Percentage change, positive or negative"

- id: set_string
  label: Set Parameter (String)
  kind: action
  params:
    - name: node_address
      type: integer
    - name: virtual_device
      type: integer
    - name: object_id
      type: integer
    - name: parameter_id
      type: integer
    - name: value
      type: string
      description: "Up to 32 ASCII characters with prefix length byte and 0x00 terminator"

- id: recall_preset
  label: Recall Parameter Preset
  kind: action
  params:
    - name: preset_id
      type: integer
      description: "4-byte preset ID number from Parameter Preset window"

Feedbacks

# Response messages returned by device:
- id: ack_valid
  label: Valid Checksum Acknowledgement
  description: "0x06 returned on valid serial message"

- id: ack_invalid
  label: Invalid Checksum Acknowledgement
  description: "0x15 returned on invalid serial checksum"

- id: set_response
  label: Set Response (Raw)
  description: "Returns current raw value of subscribed parameter"

- id: set_percent_response
  label: Set Response (Percent)
  description: "Returns current percent value of subscribed parameter"

- id: set_string_response
  label: Set Response (String)
  description: "Returns current string value of subscribed parameter"

# UNRESOLVED: specific Parameter ID values for конкретные parameters (gain, mute, source selector) - need full object/parameter reference from Audio Architect

Variables

# Parameter value scaling from source:
#
# Two-state (e.g. mute): raw values 0 and 1 (0% and 100%)
#
# Multi-state (e.g. source selector, input card gain): raw values 0,1,2,3,4... (0%-100%)
#
# Variable (e.g. gain, threshold, pan): logarithmic scaling
#   Gain: raw -280,617 (0% -80dB) to 100,000 (100% +10dB), unity = 0 (73.73%)
#   Scale: logarithmic -inf dB to -10dB, then linear above -10dB
#
# Meter: raw -800,000 (0% -80dB) to 400,000 (100% +40dB)
#   0dB = raw 0 (66.66%), dB value = Raw / 10,000
#
# All variable/percent parameters: Raw = percentage × 65536
#
# UNRESOLVED: конкретные parameter ID mappings - Audio Architect object browser required

Events

# Device-initiated messages (unsolicited):
# Device sends SET or SET PERCENT messages when subscribed parameter changes value
# Until UNSUBSCRIBE sent or device rebooted
#
# UNRESOLVED: specific unsolicited event types not enumerated in this source

Macros

# No explicit multi-step macros documented in this source

Safety

confirmation_required_for: []
interlocks: []
# UNRESOLVED: no safety warnings or interlock procedures in this source

Notes

Message Encoding

All London DI messages: start 0x02, end 0x03. Last byte = single-byte XOR checksum of body before byte substitution.

Byte Substitution

After checksum calculation, these bytes are substituted:

  • 0x02 → 0x1B 0x82
  • 0x03 → 0x1B 0x83
  • 0x06 → 0x1B 0x86
  • 0x15 → 0x1B 0x95
  • 0x1B → 0x1B 0x9B

Addressing Hierarchy

Node Address (2 bytes):  0x0001–0xFFFE (identifies physical device)
Virtual Device (1 byte): Audio=0x03, Logic=0x02
Object ID (3 bytes):      Processing object category
Parameter ID (2 bytes):   Specific parameter within object

Serial vs TCP Behavior

  • Serial: 0x06 ACK on valid checksum, 0x15 NAK on invalid; 1-second retransmit timeout if no ACK
  • TCP: No acknowledgement (inherent reliability); leave socket open indefinitely

Protocol Opcodes Summary

Opcode Message Type
0x88 SET (raw)
0x89 SUBSCRIBE
0x8A UNSUBSCRIBE
0x8C RECALL PRESET
0x8D SET PERCENT
0x8E SUBSCRIBE PERCENT
0x8F UNSUBSCRIBE PERCENT
0x90 BUMP PERCENT
0x91 SET STRING

Provenance

source_domains:
  - bssaudio.com
  - help.harmanpro.com
source_urls:
  - https://bssaudio.com/en/support_downloads
  - https://help.harmanpro.com/soundweb-london-third-party-control
  - https://help.harmanpro.com/bss
retrieved_at: 2026-04-30T15:15:19.077Z
last_checked_at: 2026-06-03T06:25:35.706Z

Verification Summary

verdict: verified
checked_at: 2026-06-03T06:25:35.706Z
matched_actions: 9
action_count: 9
confidence: medium
summary: "All spec actions verified against source (13 unresolved item(s) noted in Known Gaps.)"

Known Gaps

- "specific model numbers (BLU-50v2, BLU-100, etc.) not listed in this source document"
- "baud rate not stated in source; configured via Audio Architect Properties window"
- "data_bits, parity, stop_bits not stated in source"
- "power commands not explicitly documented in this source"
- "routing commands not explicitly documented in this source"
- "specific Parameter ID values for конкретные parameters (gain, mute, source selector) - need full object/parameter reference from Audio Architect"
- "конкретные parameter ID mappings - Audio Architect object browser required"
- "specific unsolicited event types not enumerated in this source"
- "no safety warnings or interlock procedures in this source"
- "specific model variants (BLU-50v2, BLU-100, BLU-320, etc.) — source covers general Soundweb London family only"
- "preset storage/management commands beyond RECALL PRESET"
- "firmware version compatibility"
- "configurable parameters (baud rate, port) default values not stated in source — configured via Audio Architect"

From the AI4AV catalog (https://ai4av.net) · ODbL-1.0