200G-FR4 QSFP56 is a Multi-Vendor MSA Compatible 200G-FR4 QSFP56 (Quad Small Form-Factor Pluggable) Transceiver designed for operation over Single-Mode Fiber (SMF). 200GBASE-FR4 QSFP56 has a QSFP form factor, built in 200G PAM4 (Pulse Amplitude Modulation 4-level) DSP (Digital Signal Processor) and module supports four electrical interface lanes, which can operate in 50G PAM4 encoding mode resulting in 200G (4x50G) data rate. 200G-QSFP56-2.1 modules can become handy in Data Center environments where we would have several 200G signals coming from the server side (NICs) which need to be aggregated by the Data Center switch. Module has a minimum guaranteed optical budget of 4 dB, which in most cases is enough to reach 2 km over OS2 singlemode fiber with FEC support. However, distance is just an indicative parameter calculated for comfort of identification. Eventually we calculate distance taking in account minimal optical budget and average attenuation of optical cabling in industry. 200G-FR4 QSFP56 uses 4 channel (1271/1291/1311/1331nm) 53.125 Gbps DFB Lasers and 4 channel (1271/1291/1311/1331nm) 53.125 Gbps PIN photodiode receivers. Module supports DDM/DOM optical diagnostics, which provide diagnostic information about the present operating conditions. 200GBASE-FR4 QSFP56 operates in the standard 0°-70°C temperature range and has a double LC optical connector and 38 pins F-tone Networks connector for electrical interface. 200GBASE-FR4 QSFP56 supports 212.5 Gbps data rate and such applications as 200G Ethernet.