{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7518-4FX00-1AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7518-4FX00-1AB0","canonicalUrl":"https://aoctrl.com/siemens/6ES7518-4FX00-1AB0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7518-4FX00-1AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP, 6ES7518-4FX00-1AB0, failsafe controller with 32 kB process image, PROFIsafe V2.4/V2.6, 1 Gbps interface, -40°C to 70°C.","salesMarkdown":"## CPU 1518F-4 PN/DP — the failsafe workhorse for demanding lines The 6ES7518-4FX00-1AB0 is a SIMATIC S7-1500 CPU 1518F-4 PN/DP, the failsafe variant of the 1518 series. It handles both standard and safety logic on one CPU, with PROFIsafe V2.4 / V2.6 support for SIL 3 safety applications up to the process image limits. The process image is 32 kB for inputs and 32 kB for outputs — all I/O data lives in the process image, so no remanent data shuffling for fast logic scans. That matters when you're running a coordinated safety shutdown sequence across multiple remote racks. If your line sees freeze-thaw cycles or a hot summer afternoon inside a non-climate-controlled panel, this CPU handles it without derating. ## Network interfaces and protocol support The X3 interface supports 1 Gbps, which is the high-speed backplane for PROFINET IO — only possible on the CPU 1518. The X1 and X2 interfaces run at 100 Mbps for standard PROFINET and MRP rings. MRP is supported as both redundancy manager and client, so this CPU can sit at the heart of a media-redundant ring without an external switch. MRPD is also supported, but requires IRT — note that IRT is not listed as supported on this variant, so MRPD may be unavailable in practice. Protocol stack includes TCP/IP, UDP, DHCP, DNS, DCP, LLDP, SNMP, HTTP/HTTPS (standard and user pages), and MODBUS TCP. The RS-485 interface at X4 supports point-to-point serial communication for legacy drives or remote I/O. ## Programming languages and safety integration Supported programming languages include LAD, FBD, STL, SCL, and GRAPH — both standard and failsafe variants for LAD and FBD. That means you can reuse existing safety function blocks from older S7-300/400 F-systems without rewriting them in a different language. Integrated PID controllers are available for temperature and valve positioning, both with integrated optimization. This saves a separate loop controller for simple thermal or flow loops. For a BOM freeze or critical-spare holding, this is the failsafe variant you want in the cabinet before the line goes down. The wide temperature range and PROFIsafe support make it a one-for-one swap for any existing 1518F-4 PN/DP installation.","metaTitle":"Siemens 6ES7518-4FX00-1AB0 CPU 1518F-4 PN/DP, 1 Gbps","metaDescription":"Siemens 6ES7518-4FX00-1AB0 CPU 1518F-4 PN/DP, failsafe controller with PROFIsafe V2.4/V2.6, 32 kB process image, -40°C to 70°C, 1 Gbps X3 interface. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["PLCs (Programmable Logic Controllers)"],"specifications":{"DCP":"Yes","DNS":"Yes","FBD":"Yes; incl. failsafe","I2t":"0.02 A²·s","IRT":"No","LAD":"Yes; incl. failsafe","MRP":"Yes; as MRP redundancy manager and/or MRP client","SCL":"Yes","STL":"Yes","UDP":"Yes","DHCP":"Yes","HTTP":"Yes; Standard and user pages","LLDP":"Yes","MRPD":"Yes; Requirement: IRT","Max.":"70 °C","Min.":"-40 °C","SNMP":"Yes","Type":"Hardware clock","Depth":"129 mm","GRAPH":"Yes","HTTPS":"Yes; Standard and user pages","Width":"175 mm","Height":"147 mm","Inputs":"32 kbyte; All inputs are in the process image","MODBUS":"Yes; MODBUS TCP","Number":"16","RS 485":"Yes; X4","TCP/IP":"Yes","Via CM":"8; A maximum of 8 CMs/CPs (PROFIBUS, PROFINET, Ethernet) can be inserted in total","Forcing":"Yes","Outputs":"32 kbyte; All outputs are in the process image","Present":"Yes","100 Mbps":"Yes","I&M data":"Yes; I&M0 to I&M3","PID-Temp":"Yes; PID controller with integrated optimization for temperature","1000 Mbps":"Yes; Only possible at the X3 interface of the CPU 1518","ERROR LED":"Yes","MAINT LED":"Yes","PID_3Step":"Yes; PID controller with integrated optimization for valves","PROFIsafe":"Yes; V2.4 / V2.6","Per Probe":"40","Supported":"Yes","Variables":"Inputs/outputs, memory bits, DBs, distributed I/Os, timers, counters","Adjustable":"Yes","Encryption":"Yes; Optional","Integrated":"2","S7 routing":"Yes","Size, max.":"16 kbyte","Web server":"Yes","Backup time":"6 wk; At 40 °C ambient temperature, typically","IP protocol":"Yes; IPv4","Lower Limit":"adjustable minimum cycle time","PID_Compact":"Yes; Universal PID controller with integrated optimization","PROFIenergy":"Yes; per user program","Single step":"No","Upper Limit":"adjustable maximum cycle time","Via Dataset":"Yes","Autocrossing":"Yes","Equidistance":"Yes","Number range":"0 ... 65 535","RUN/STOP LED":"Yes","Status block":"Yes; Up to 16 simultaneously (in total across all ES clients)","in AS, slave":"Yes","OPC UA Client":"Yes","OPC UA Server":"Yes; Data access (read, write, subscribe), method call, custom address space","Per Cam Track":"160","Shared device":"Yes","UDP multicast":"Yes; 128 multicast circuits (of which max. 5 via X1)","in AS, master":"Yes","to DP, master":"Yes","Motion Control":"Yes; Note: The number of technology objects affects the cycle time of the PLC program; selection guide via the TIA Selection Tool","Number of keys":"6","Per Output Cam":"20","Program alarms":"Yes","Updating times":"The minimum value of the update time also depends on communication share set for PROFINET IO, on the number of IO devices, and on the quantity of configured user data","Autonegotiation":"Yes","Copy protection":"Yes","Inputs (volume)":"8 kbyte","Number of ports":"1","Weight, approx.":"2 117 g","lifecycle_stage":"current","Block protection":"Yes","Firmware version":"V2.9","Isochronous mode":"No","Maintenance-Free":"Yes","Media redundancy":"only via 1st interface (X1)","Outputs (volume)":"8 kbyte","Power loss, typ.":"29 W","RJ 45 (Ethernet)":"Yes; X3","Rated value (DC)":"24 V","Data length, max.":"2 kbyte; 1 472 bytes for UDP broadcast","H-Sync forwarding":"Yes","Integrated Switch":"No","Number of PtP CMs":"the number of connectable PtP CMs is only limited by the number of available slots","PROFIBUS DP slave":"No","Repeat rate, min.":"1/s","Security policies":"Available security policies: None, Basic128Rsa15, Basic256Rsa15, Basic256Sha256","Forcing, variables":"Peripheral inputs/outputs","High-speed counter":"Yes","PROFIBUS DP master":"Yes","PROFINET IO Device":"No","Per Priority Class":"24","Retentivity preset":"No","Data record routing":"Yes","PG/OP communication":"Yes","Prioritized startup":"No","User authentication":"\"anonymous\" or by user name & password","on Ethernet via NTP":"Yes","Direct data exchange":"No","HW functional status":"FS03","ISO-on-TCP (RFC1006)":"Yes","Inrush current, max.":"2.7 A; Rated value","Mode selector switch":"1","Number of IO modules":"16 384; max. number of modules / submodules","Password for display":"Yes","Per External Encoder":"80","Per Positioning Axis":"80","Per Synchronous Axis":"160","Screen diagonal [cm]":"6.1 cm","Alarms and Conditions":"Yes","Integrated (For Data)":"60 Mbyte","Number of breakpoints":"20","Number of lines, max.":"1","Number of startup OBs":"100","Open IE communication":"Yes","SIL acc. to IEC 61508":"SIL 3","SIMATIC communication":"Yes","Counting and measuring":"Yes","For Send Cycle Of 1 Ms":"1 ms to 512 ms","For Send Cycle Of 2 Ms":"2 ms to 512 ms","For Send Cycle Of 4 Ms":"4 ms to 512 ms","Modules per rack, max.":"32; CPU + 31 modules","Of Which In Line, Max.":"128","PROFINET IO Controller":"No","Retentivity adjustable":"Yes","Asset management record":"Yes; per user program","Deviation per day, max.":"10 s; Typ.: 2 s","Number of entries, max.":"3 200","Sampling interval, min.":"10 ms","Status/control variable":"Yes","Transmission rate, max.":"12 Mbit/s","User data per job, max.":"See online help (S7 communication, user data size)","For Bit Operations, Typ.":"1 ns","Integrated (For Program)":"9 Mbyte","Number of DPV1 alarm OBs":"3","Number of clock memories":"8; 8 clock memory bit, grouped into one clock memory byte","Number of free cycle OBs":"100","Number of program alarms":"4 000","Number of sessions, max.":"64","Number of time alarm OBs":"20","Of Which Powerfail-Proof":"1 000","Per Priority Class, Max.":"64 kbyte; max. 16 KB per block","Runtime license required":"Yes; \"Large\" license required","Current consumption, max.":"2 A","For Send Cycle Of 125 μS":"125 µs","For Send Cycle Of 250 μS":"250 µs to 128 ms","For Send Cycle Of 500 μS":"500 µs to 256 ms","For Word Operations, Typ.":"2 ns","Number of delay alarm OBs":"20","Number of variables, max.":"200","Per Speed-Controlled Axis":"40","Publishing interval, min.":"10 ms","Size of ODK SO file, max.":"9.8 Mbyte","Application authentication":"Yes","Number of S7 routing paths":"64; in total, only 16 S7-Routing connections are supported via PROFIBUS","Number of elements (total)":"20 000; Blocks (OB, FB, FC, DB) and UDTs","For Send Cycle Of 187.5 μS":"187.5 µs","Number of connections, max.":"40","Number of process alarm OBs":"50","Reverse polarity protection":"Yes","S7 communication, as client":"Yes","S7 communication, as server":"Yes","Vertical Installation, Max.":"40 °C; Display: 40 °C, at an operating temperature of typically 40 °C, the display is switched off","Vertical Installation, Min.":"0 °C","SIMATIC memory card required":"Yes","Connection display LINK TX/RX":"Yes","Horizontal Installation, Max.":"60 °C; Display: 50 °C, at an operating temperature of typically 50 °C, the display is switched off","Horizontal Installation, Min.":"0 °C","Number of PROFIBUS interfaces":"1","Number of PROFINET interfaces":"3","Number of configurable Traces":"8; Up to 512 KB of data per trace are possible","Industrial Ethernet status LED":"Yes","MRP interconnection, supported":"Yes; as ring node according to IEC 62439-2 Edition 2.0","Number of cyclic interrupt OBs":"20; With Failsafe, two RTGs with one \"Cyclic interrupt OB\" or one \"Free cycle OB\" (F-OB) each are possible","Number of diagnostic alarm OBs":"1","Number of isochronous mode OBs":"3","Number of server methods, max.":"100","Number of synchronous error OBs":"2","Of Which Status Variables, Max.":"200; per job","For Fixed Point Arithmetic, Typ.":"2 ns","Number of asynchronous error OBs":"4","Number of distributed IO systems":"64; A distributed I/O system is characterized not only by the integration of distributed I/O via PROFINET or PROFIBUS communication modules, but also by the connection of I/O via AS-i master modules or links (e.g. IE/PB-Link)","Of Which Control Variables, Max.":"200; per job","Current consumption (rated value)":"1.7 A","Infeed power to the backplane bus":"12 W","Number of server interfaces, max.":"10; or 20, depending on type of server interface","Number of subprocess images, max.":"32","Number of registerable nodes, max.":"50 000","Of which IO devices with IRT, max.":"64","Protection level: Write protection":"Yes","For Floating Point Arithmetic, Typ.":"6 ns","Joint commission (Team Engineering)":"Yes; Parallel online access possible for up to 10 engineering systems","Number of IO Devices per tool, max.":"8","Plug-in (SIMATIC Memory Card), max.":"32 Gbyte; the memory card must have at least 2 GB of space on it","Switchover time on line break, typ.":"200 ms; For MRP, bumpless for MRPD","permissible range, lower limit (DC)":"19.2 V","permissible range, upper limit (DC)":"28.8 V","Activation/deactivation of DP slaves":"Yes","Number of accessible variables, max.":"200 000","Number of stations in the ring, max.":"50","activation/deactivation of I-devices":"Yes; per user program","Protection level: Complete protection":"Yes","Number of connectable IO Devices, max.":"128; In total, up to 1 000 distributed I/O devices can be connected via AS-i, PROFIBUS or PROFINET","Number of alarms for system diagnostics":"1 000","Number of slots for SIMATIC memory card":"1","Protection level: Read/write protection":"Yes","Mains/voltage failure stored energy time":"5 ms","Number of subscriptions per session, max.":"20","available (for Linux runtime application)":"1 Gbyte","Integrated (for C/C++ Runtime application)":"512 Mbyte","Number of technology synchronous alarm OBs":"2","Performance level according to ISO 13849-1":"PLe","Installation altitude above sea level, max.":"5 000 m; Restrictions for installation altitudes > 2 000 m, see manual","Number of monitored items, recommended max.":"10 000; for 1 s sampling interval and 1 s send interval","User program protection/password protection":"Yes","Number of configurable program messages, max.":"10 000; Program messages are generated by the \"Program_Alarm\" block, ProDiag or GRAPH","Number of connectable IO Devices for RT, max.":"128","Number of connections reserved for ES/HMI/web":"10","Number of alarms for motion technology objects":"480","Low demand mode: PFDavg in accordance with SIL3":"< 2.00E-05","Number of connections via integrated interfaces":"320","Several Passive Connections Per Port, Supported":"Yes","Number of inputs/outputs per server method, max.":"20","Number of loadable program messages in RUN, max.":"5 000","Number of IO Controllers with shared device, max.":"4","With IRT and parameterization of \"odd\" send cycles":"Update time = set \"odd\" send clock (any multiple of 125 µs: 375 µs, 625 µs ... 3 875 µs)","Power consumption from the backplane bus (balanced)":"35 W","Number of login stations for message functions, max.":"64","integrated (for CPU function library of CPU Runtime)":"50 Mbyte; Note: The \"CPU function library of the CPU\" are C/C++ blocks for the user program that were created using the SIMATIC ODK 1500S or Target 1500S.","STEP 7 TIA Portal configurable/integrated from version":"V17 (FW V2.9) / V15 (FW V2.5) or higher","High demand/continuous mode: PFH in accordance with SIL3":"< 1.00E-09","Number of nodes for user-defined server interfaces, max.":"30 000","Retentive data area (incl. timers, counters, flags), max.":"768 kbyte; In total; available retentive memory for bit memories, timers, counters, DBs, and technology data (axes): 700 KB","Number of nodes of the client interfaces, recommended max.":"5 000","Number of inputs/outputs when calling OPC_UA_MethodCall, max.":"20","Number of registerable method calls of OPC_UA_MethodCall, max.":"100","Extended retentive data area (incl. timers, counters, flags), max.":"20 Mbyte; When using PS 6 0W 24/48/60 V DC HF","Number of available Motion Control resources for technology objects":"15 360","Number of elements for one call of OPC_UA_MethodGetHandleList, max.":"100","Number of elements for one call of OPC_UA_NameSpaceGetIndexList, max.":"20","Number of positioning axes at motion control cycle of 4 ms (typical value)":"140","Number of positioning axes at motion control cycle of 8 ms (typical value)":"192","Number of IO Devices that can be simultaneously activated/deactivated, max.":"8; in total across all interfaces","Number of simultaneous calls of the client instructions for data access, per connection, max.":"5","Number of simultaneous calls of the client instructions for session management, per connection, max.":"1"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/4f25641e71864c4eda289a3f658410db.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1093818&mlfb=6ES7518-4FX00-1AB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/6ES7518-4FX00-1AB0/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional alternative to 6ES7518-4FX00-1AB0?","answer":"The 6ES7518-4TP00-0AB0 is the standard (non-failsafe) variant of the same CPU 1518-4 PN/DP. It drops into the same panel footprint and shares the same 32 kB process image and 1 Gbps X3 interface, but lacks PROFIsafe and failsafe programming support. If your application requires safety logic, stick with the 4FX00 variant."},{"question":"What compliance documentation is available for this CPU?","answer":"Standard Siemens SIMATIC S7-1500 documentation applies: CE, UKCA, cULus, and EAC declarations are available. RoHS and REACH compliance is standard for this generation. The specific declaration of conformity can be provided with the order."},{"question":"Does this CPU support DCP and DNS?","answer":"Yes, DCP (Discovery and Configuration Protocol) and DNS (Domain Name System) are both supported for PROFINET network configuration and name resolution."},{"question":"Will 6ES7518-4FX00-1AB0 drop into a panel specified for 6ES7518-4TP00-0AB0?","answer":"Yes, the mechanical dimensions are identical — 175 mm wide, 147 mm high, 129 mm deep. The mounting rails and backplane bus connectors are the same. No rewiring is needed; the only difference is the failsafe firmware and PROFIsafe support."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7518-4FX00-1AB0","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/6ES7518-4FX00-1AB0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}