德国赫斯曼交换机 RS20系列 RS20-0400T1T1SDAEHC RS20-0400T1T1SDAPHC RS20-0400M2M2SDAEHC RS20-0400M2M2SDAPHC RS20-0400S2S2SDAEHC RS20-0400S2S2SDAPHC 8口固定端口交换机 RS20-0800T1T1SDAUHC RS20-0800T1T1SDAEHC RS20-0800T1T1SDAPHC RS20-0800M2M2SDAUHC RS20-0800M2M2SDAEHC RS20-0800M2M2SDAPHC RS20-0800S2S2SDAUHC RS20-0800S2S2SDAEHC RS20-0800S2S2SDAPHC RS30-0802T1T1SDAEHC RS30-0802T1T1SDAPHC RS30-0802O6O6SDAE