With the development of the information society, people have higher and higher requirements for the capacity, transmission rate and service level of the communication system.
As a result, the application of optical modules is also more and more extensive, the rate of optical modules, packaging, power consumption and functionality is also toward the direction of high speed, small size, low power consumption and multi-function development. Today we will talk about the DDM function in the optical module.
Functions of DDM
DDM technology in optical modules provides a means of module performance monitoring that can help managers predict module life, locate system faults, and detect module compatibility.
Common Functions
- monitor operating temperature
- operating voltage monitoring
- monitor operating current
- Monitoring TX and RX power
- display factory information of the optical transceiver
- Timely warning/alarm
Important parameters to monitor
DDM enables users to monitor parameters that help them operate their transceivers more efficiently. These five basic parameters are common across all standards.
Case temperature: Mon_temp
Supply voltage: Mon_Vcc
Receiver input power: Mon_Rxpwr
Transmitter LD bias current: Mon_Txbias
Transmitter output power: Mon_Txpwr
For information on which Sanopti transceiver modules support DDM, see the Sanopti website: https://sanopti.com/
Two Roles of DDM Technology
Fault localization
During the operation of optical services, faults are inevitable. Digital diagnostic monitoring technology can help network administrators quickly locate faults and shorten troubleshooting and repair time. Through the digital diagnostic function, the warning status of transmit optical power, receive optical power, current, voltage and temperature can be comprehensively analyzed, so as to quickly locate and solve the problem.
Compatibility Test
Digital diagnostics also verifies module compatibility. The purpose of compatibility verification is to analyze whether the module's running environment is compatible with the data sheet or related standards.Only in this compatible operating environment, the performance of the module can be guaranteed. In some cases, environmental parameters that do not comply with the datasheet or the relevant standards can lead to a degradation of the module's performance, which can result in transmission errors.
By monitoring the operating voltage and operating temperature inside the optical transceiver in real time, the system administrator can identify some potential problems:
If the Vcc voltage is too high, it will breakdown the CMOS device.
If the Vcc voltage is too low, the laser will not work properly.
If the received power is too high, the receiver module can be damaged.
If the operating temperature is too high, it will accelerate the aging of the device. Furthermore, by overseeing the optical power received, it becomes possible to manage the functionality of both the circuit and the distant transmitter.
About The Units uWatts And dBm
The optical power provided by the transceiver module is in units of 0.1 uW. Measured Tx and Rx power in mW per SFF-8472. Power is provided as a 16-bit unsigned integer, with power defined as a full 16-bit value (0-65535) with LSB equal to 0.1uW and a total range of 0 to 6.5535 mW (~ -40 to +8.2 dBm).
Most optical power displays are in dBm (decibel/milliwatt). Decibel is the ratio of two power levels, one of which is considered the reference value. db is logarithmic scale. The m in dBm refers to the reference power, which is 1 milliwatt.
How To Use DDM Data
Configuration Example: Digital Diagnostic Monitor
The following example shows how to display DDM test information on a device:
Eample
Device>Enable
Device #Configuration Terminal
device(config)# show interface sfp ethernet 1/1
Transceiver type: SFP
Compliance 10G BASE-LR
Connector type: LC
Wavelength (nm): 1310
Transmission distance (meters): 10000 (9um)
Digital Diagnostic Monitoring: Yes
Supplier name: WTD
Manu. Serial number: BP132500260047
Production date:2013-06-19
Supplier name: WTD
Temperature (℃): 28
Voltage (V): 3.3098
Bias current (mA): 35.419
Bias high threshold (mA): 70.00
Bias low threshold (mA): 15.00
Received power (dBm): -2.80
Receive power high threshold (dBm): 0.00
Receive power low threshold (dBm): -15.20
Transmit power (dBm): -3.10
Transmit power high threshold (dBm): 0.00
Transmit power low threshold (dBm): -8.20
Application of DDM
Common Uses
The DDM feature of a transceiver provides a performance monitoring tool to help the system manage and predict transceiver life, isolate faulty systems, and verify transceiver compatibility in an installation.
Optical transceivers with DDM look the same as optical transceivers without DDM, but the internal circuitry is somewhat different. If an optical transceiver does not have DDM, it will not indicate an alarm if there is a problem with the product.
Potential Uses of DDM Data
Optical degradation monitoring
Using information returned by DDM-enabled optical modules, optical performance degradation can be monitored and events triggered based on custom or factory-programmed warning and alarm thresholds.
Link or router failure isolation
Utilizing the information returned by DDM-enabled optical modules, any optical issues affecting the port can be quickly identified or eliminated as a potential source of problems.
Conclusion
From the above, we can know that DDM has a great role in the optical transcetator. As a side of the monitoring data, the quality of the light collection hair device is escorted. If you have any questions, please contact us at any time.
