Key Specifications:

• Interface Type: Analog 2-wire telephone line
• Supported Telephone Sets: Standard analog telephones (up to 8 sets per unit)
• Power Supply: 48 V DC from the DCS communication bus
• Communication Protocol: Proprietary Yokogawa DCS communication protocol over the F Fieldbus (FF) / Vnet/IP backbone
• Line Impedance: 600 Ω nominal
• Number of Channels: 4 telephone lines (2 lines per port, 2 ports)
• Audio Format: Standard analog voice (300 Hz – 3400 Hz bandwidth)

Functional Features:

• Incoming Call Display: Caller identification displayed on the DCS operator station screen
• Hands-Free Operation: Full-duplex speakerphone capability for operator stations
• Internal Calling: Intercom functionality between operator stations via the DCS network
• Emergency Broadcast: Priority paging and emergency announcement override capability
• Auto-Answer: Configurable automatic answer for designated telephone lines
• Call Logging: Integrated call event logging within the DCS historian

Structural Characteristics:

• Form Factor: Compact DIN rail-mountable module
• Dimensions: Approximately 130 mm (W) × 180 mm (H) × 90 mm (D)
• Housing Material: Flame-retardant ABS plastic (UL94 V-0 rated)
• Connector Type: RJ-11 jacks for telephone line connection; DB-9 or terminal block for DCS bus connection
• Weight: Approximately 0.8 kg

Operating Principle:
The AXW4A receives voice signals from analog telephone sets via 2-wire analog lines, converts them into digital data packets, and transmits them over the DCS communication network (F Fieldbus / Vnet/IP) to the designated operator station. Conversely, outgoing voice from the operator station is converted back to analog audio and sent to the telephone set. The unit operates as a protocol converter between the analog telephony domain and the digital DCS domain.

Advantages & Highlights:

• Seamless DCS Integration: Direct plug-in compatibility with CENTUM VP/CS 3000 racks
• Reliable Voice Quality: Low-latency analog-to-digital conversion with minimal audio distortion
• Scalable Configuration: Support for up to 8 telephone sets per unit with flexible line assignment
• Emergency Priority: Dedicated emergency override function for safety-critical announcements

Applicable Industries:

• Oil & Gas Refining
• Petrochemical Plants
• Power Generation
• Water & Wastewater Treatment
• Pulp & Paper

Installation Requirements:

• Mount on standard 35 mm DIN rail inside the DCS control room cabinet
• Ensure 48 V DC power is available from the DCS communication power supply
• Telephone line cabling must use shielded twisted pair (STP) with maximum length of 500 m
• Maintain minimum 10 mm clearance on all sides for heat dissipation

Usage Precautions:

• Do not connect digital or IP telephone sets directly; only analog 2-wire telephones are supported
• Verify line impedance matches 600 Ω standard before connection
• Do not expose the unit to temperatures exceeding 55 °C or humidity above 85% RH (non-condensing)
• Ground the unit chassis to the DCS cabinet ground bus to prevent electrical noise