RS485 to Optical Converter VME RTM
Project Description
Overview
The CONV-RS485-OPT-RTM is a VME rear transition module providing fiber-optic and electrical inputs and outputs. In combination with the CONV-TTL-RS485 as front-module it provides TTL to optical conversion. The interface with the CONV-TTL-RS485 is through internal RS485 signaling. A block diagram of the board is shown below.
The design is based on the existing modules: optical transmitter CTDAB and optical receiver CTDPR.
Specifications
Note this is preliminary content.
Parameter | Value |
Supported fiber type | Single mode |
Fiber connector | ST |
Allowed attenuation | max 10dB (10km fiber with 10 connections) |
Optical signal characteristics | Transmission/ Reception of CERN's GMT signal (500 kHZ DC balanced signal) and of single pulses: Minimum pulse width: 100 ns Maximum frequency: 1 MHz Maximum pulse width: 1 ms Minimum frequency: None, as long as maximum pulse width is respected |
Latency due to electronics | 14 ns based on current system performance; measurement taken by triggering on the TTL input of the optical transmitter and measuring at the TTL output of the optical receiver, using only few cm of fiber |
Jitter due to electronics | <10 ns based on current system performance; measurement taken by triggering on the TTL input of the optical transmitter and measuring at the TTL output of the optical receiver, using only few cm of fiber |
Project Information
- Design-notes
- V1-Schematic-Review
- V1-PCB-Review
- Level Conversion project
- Presentation on level converter boards
- Presentation on design specification
Status
Date | Event |
15-07-2017 | Start working on project. |
06-09-2017 | First schematics for a prototype. |
27-10-2017 | Prototypes received |
06-12-2017 | Prototypes validated |
08-12-2017 | Meeting and presentation to discuss design choices and outstanding issues |
15-12-2017 | V1-Schematic-Review held at CERN BE-CO-HT |
02-02-2018 | V1-PCB-Review held at CERN BE-CO-HT |
Denia Bouhired-Ferrag - Erik van der Bij - Eva Gousiou - Dimitris Lampridis - February, 2018