Technical Specifications (Parameters) Parameter Specification Product Type Logic controller Product Range Modicon M251 Rated Supply Voltage [Us] 24 V DC Supply Voltage Limits 20.4...28.8 V Inrush Current 50 A Power Consumption 32.6...40.4 W (with max I/O expansion) Memory Capacity 64 MB system memory RAM Data Backed Up 128 MB built-in flash memory for user programs Data Storage Equipment ≤ 16 GB SD card (optional) Execution Time per 1 KInstruction 0.3 ms (event/periodic tasks); 0.7 ms (other instructions) Real-Time Clock Yes (with ≤ 60 s/month drift at 25°C) Battery Type BR2032 lithium non-rechargeable (4-year life) Integrated Connections USB mini-B, serial RJ45 (RS232/RS485), dual-port Ethernet RJ45, CANopen SUB-D 9 Communication Protocols Modbus TCP client/server, Ethernet/IP slave, Modbus RTU/ASCII master/slave, CANopen DS301 V4.02, FTP client/server, SNMP, OPC UA server, web server Maximum I/O Expansion 7 modules (local), 14 modules (remote) Number of CANopen Slaves 63 Ethernet Ports 2 x RJ45 (dual-port switch), 10BASE-T/100BASE-TX, auto-negotiating Serial Line Transmission Rate 1.2...115.2 kbit/s (RS485, 15m); 1.2...115.2 kbit/s (RS232, 3m) USB Transmission Rate 480 Mbit/s (3m) Electrical Connection Removable screw terminal block (power supply, 5.08mm pitch) Mounting Support Top hat TH35-15/TH35-7.5 rail (IEC 60715) or panel with fixing kit IP Degree of Protection IP20 (with protective cover) Operating Temperature -10...55°C (horizontal); -10...35°C (vertical) Storage Temperature -25...70°C Dimensions (W x H x D) 54 mm x 90 mm x 95 mm Net Weight 0.22 kg Standards IEC 61131-2:2007, UL 508, CSA C22.2 No 142/213, Marine specifications (LR, ABS, DNV, GL) Product Certifications cULus, CE, UKCA, DNV-GL, ABS, LR Sustainable Status Green Premium product (RoHS, REACh compliant, PVC-free, Mercury-free)