Overview
IEC 62343-4-1:2016 defines the software and hardware interface for a 1 x 9 wavelength selective switch (WSS) - a dynamic module used in DWDM/ROADM systems to route and attenuate individual wavelength channels. The standard specifies how a host controller (HC) or resident firmware controls the WSS, how status and alarm information are exposed, and the electrical and memory interfaces used for command/response (notably a DPRAM interface and optional RS232).
Key topics and technical requirements
- Interface scope: Configuration and function to control a 1 x 9 WSS - retrieve switch status, set switch mapping and attenuation, and store settings in non‑volatile memory.
- Primary control paths:
- DPRAM interface: 12‑bit address bus and 16‑bit data bus between HC and WSS module; DPRAM control signals include R/W, CE (active low), OE (active low).
- RS232: Optional serial TxD / RxD channel for communication.
- Control and status signals:
- START (active low input) to trigger commands
- DONE, ERROR outputs for command completion/status
- BUSY (active low) to indicate contention on DPRAM
- MASTER RESET and SOFT RESET inputs
- READY (asserted as logic 0) and ALARM outputs
- Memory and commands:
- DPRAM memory map (examples shown in the standard): e.g., 0x0001 = hardware/software version (RO); 0x0020 = command register (RW); 0x0021 = command code (RW); 0x0022 = command data 1 (RW)
- Annex B provides detailed DPRAM memory map variations and timing charts for read/write cycles, power on, reset and alarm timing.
- Electrical details:
- Interface operates at low voltage +3.3 V logic levels
- Annex A gives connector form, pin assignment, supply and threshold details (electrical connector and supply current specs are included in the standard).
Applications and who uses it
- Module manufacturers: implement the standardized DPRAM/RS232 interface and pinout so their 1 x 9 WSS modules are interoperable with host controllers.
- Firmware and hardware engineers: develop resident firmware, FPGA/DSP logic, and host drivers that follow the command register map and timing requirements.
- System integrators and network equipment vendors: integrate WSS modules into ROADMs and chassis using consistent control and alarm semantics.
- Test labs / certification bodies: verify compliance with DPRAM timing, reset behavior and functional command responses.
- Network operators: benefit indirectly via predictable control, consistent status reporting and reliable non‑volatile configuration storage for DWDM networks.
Related standards
- IEC 62343 (Dynamic modules - general guidance)
- IEC 60050-731 (Optical fibre communication vocabulary) - normative references used in the standard
Keywords: IEC 62343-4-1:2016, wavelength selective switch, WSS, 1x9 WSS, DPRAM interface, RS232, DWDM, ROADM, firmware interface, optical networking, module control.