Siemens CM 1542-1 Operating Instructions Manual

Properties and functions1.3 Configuration limits and performance dataCM 1542-1Operating Instructions, 07/2019, C79000-G8976-C355-04 15NoteConnection resources of the CPUDepending on the CPU type, different numbers of connection resources are available. Thenumber of connection resources is the decisive factor for the number of configurableconnections. This means that the values that can actually be achieved may be lower thanspecified in this section describing the CM.You will find detailed information on the topic of connection resources in the function manual/4/ (Page 50).Restrictions for UDP● Restrictions UDP broadcast / multicastTo avoid overloading the CP due to high broadcast / multicast frame traffic, the receipt ofUDP broadcast / multicast on the CP is limited● UDP frame bufferingLength of the frame buffer: At least 7360 bytesFollowing a buffer overflow, newly arriving frames that are not fetched by the userprogram are discarded.1.3.4 Characteristics of S7 communicationS7 communication provides data transfer via the ISO-on-TCP protocol.Characteristic Explanation / valuesTotal number of freely usable S7 connections onIndustrial EthernetMax. 64LAN interface - data field length generated by CMper protocol data unit (PDU = protocol data unit)• for sending: 480 bytes / PDU• for receiving: 480 bytes / PDUNoteMaximum values for an S7-1500 stationDepending on the CPU you are using, there are limit values for the S7-1500 station. Note theinformation in the relevant documentation.