Logic controller | programmable | 24VDC | PROFINET | PROFIBUS | 6ES7516-3AP03-0AB0 Siemens

Technical Specifications

Model: CPU 1516-3 PN/DP | Code: 6ES7516-3AP03-0AB0 | FW: V4.0 (upgrade available)
Working memory: 2 MB (program) + 7.5 MB (data) | Retentive area: up to 512 KB (expandable up to 7.5 MB with PS 60 W HF)
Memory card: 1× SIMATIC Memory Card (up to 32 GB) – required
Performance: bit operations ~6 ns | word – 7 ns | fixed-point – 9 ns | floating-point – 37 ns
Interfaces:
• PROFINET X1: IRT, 2-port switch, IO Controller/Device, MRP/MRPD, synchronous clock
• PROFINET X2: RT, IO Controller/Device
• PROFIBUS DP (X3, RS-485): DP Master, up to 12 Mbit/s, synchronous/equidistant mode

Network/IIoT: OPC UA Server (DA, Method, A&C, RBAC) and Client; open IE protocols (TCP/UDP, ISO-on-TCP), HTTPS/Web server, LLDP, SNMP, DHCP/DNS, S7 communication (TLS 1.3), PROFIenergy
Control/technology: Motion Control (up to 2400 resources), PID_Compact / PID-3Step / PID-Temp, high-frequency counting, isochronous mode (IRT/DP)
OB/DB/FB/FC limits: up to 8000 objects; DB up to 7.5 MB (with absolute addressing – up to 64 KB), OB/FB/FC up to 1 MB
I/O space: Inputs 32 KB / Outputs 32 KB; up to 8192 modules/submodules; up to 64 distributed I/O systems
Connections: up to 256 (128 via integrated interfaces), 10 reserved for ES/HMI/Web; S7 routing
Diagnostics: 3200-entry buffer (500 power-fail-proof), Trace (4× up to 512 KB), SysLog
Display/controllers: 6.1 cm display, 8 keys, 2 mode buttons (RUN/STOP)
Power supply: 24 V DC (19.2…28.8 V), typ. 0.69 A (max 1.08 A), polarity protection; energy buffering ~5 ms
Energy: backplane bus 12 W; typ. losses 4 W
Environment: −30…+60 °C (horizontal), up to 5000 m altitude; IP protection depends on enclosure; Eco Profile/EPD data
Dimensions/weight: 70 × 147 × 129 mm; ~469 g
TIA Portal: from V20 (FW V4.0) | compatible with older 6ES7516-3AN02-0AB0 (configuration compatibility)

Functions

Fast cycle and IRT/isochronous mode – deterministic control for synchronous axes and high-speed lines.

Integrated multi-protocol communication – 2× PROFINET + PROFIBUS DP master, OPC UA (server/client), Web/HTTPS.

Advanced diagnostics and trace – for quick commissioning, debugging, maintenance, and data analysis.

Cybersecurity – Secure Boot, signed FW, role-based access, TLS 1.3, program protection.

Technological objects – Motion Control, PID, high-frequency counting, clock synchronization.

Collaborative engineering – Team Engineering (up to 8 ES simultaneously), online status/control variables.

Usage

For engineers/automation specialists: fast cycles, IRT, MRP/MRPD rings, OPC UA integration with SCADA/MES/ERP, extensive diagnostics, simple trace.

For electricians/service staff: DIN modules up to 32 per rack, integrated display and LEDs, clear diagnostics, standard PROFINET/PROFIBUS topologies, easy replacement via separate memory card.

For machine builders: high performance, technology objects, prioritized startup, up to 1024 distributed I/O (via AS-i/PN/PB), high reliability.

Pros

Very high performance (6 ns) and deterministic communication (IRT/isochronous).

Universal communication: 2× PN + 1× PB, OPC UA server/client, HTTPS/Web.

Strong security features and access control (TLS, Secure Boot, RBAC).

Excellent diagnostics/trace tools – less downtime, faster startup.

Expansion and compatibility with the broad SIMATIC ecosystem and TIA Portal.

Cons

SIMATIC Memory Card is mandatory (purchased separately).

Higher price compared to basic CPUs – designed for medium/large-scale systems.

IRT/isochronous mode requires proper PN device selection and network design.