A CH represents a simplex interface. For example, the monitoring port of the 18CH CWDM MUX is a duplex interface, so 2 channels is sufficient, but if you need to match the rest of the devices (with monitoring ports), additional channel support will be required. Therefore, it is recommended that you use 4CH or 8CH OPD to allow enough channels for future use. And our OPD is an active product, it needs to be used with the FMT chassis . より FS.COM で 03.08.2018

Dear, thanks for your question, this item can only monitors total power from all channels. And if you need monitor each channel within a DWDM system, please inquiry to your sales, our newly launched OPM( Optical Performance Monitoring）can meet your demand, we will give you suitable recommendation. Thank you. より FS.COM で 22.02.2018