Zakaria El Intissar

I've spent 13 years in power system automation, electrical protection, and SCADA communication, as an automation and industrial computing engineer. ScadaProtocols.com is where I turn what I've learned on site into plain guides and working tools — so other engineers can decode, analyze, and troubleshoot industrial communication protocols without the guesswork.

Author Archives: Zakaria El Intissar

CIP Connection Manager Object Explained (Class 0x06)

Behind every Forward_Open is one object. Behind every Forward_Close, every Unconnected_Send, every “connection timeout,” every “out of connections” error — one object. The Connection Manager Object (Class 0x06) is the CIP object that allocates and manages all the connection resources in a device. If Forward_Open is the service, the Connection Manager Object is what answers the door. This… Read More: CIP Connection Manager Object Explained (Class 0x06) »

CIP Ethernet Link Object Explained (Class 0xF6)

When your I/O block reports “Link Down,” when error counters spike in Studio 5000, when a DLR ring takes longer than expected to converge — the data you need lives in the Ethernet Link Object, Class 0xF6. It’s the CIP object that holds every Ethernet-layer diagnostic on every EtherNet/IP device: link status, link speed, duplex mode, MAC address,… Read More: CIP Ethernet Link Object Explained (Class 0xF6) »

Modbus TCP on the Siemens S7-1500 (TIA Portal): MB_CLIENT and MB_SERVER

The S7-1500 talks Modbus TCP straight out of its PROFINET port. No CP module, no license, no third-party library. You drop in two instructions — MB_CLIENT and MB_SERVER — point them at a connection structure, and you have a working Modbus link. That said, the part that trips people up isn’t dropping the block in. It’s the connection… Read More: Modbus TCP on the Siemens S7-1500 (TIA Portal): MB_CLIENT and… »

CIP TCP/IP Interface Object Explained (Class 0xF5)

Every EtherNet/IP device has an IP address. Every device has a subnet mask and a gateway. Every device decides whether to get its address from DHCP, BOOTP, or static configuration. Every device that participates in multicast I/O has a multicast address range. All of this lives in one CIP object — the TCP/IP Interface Object, Class 0xF5. When… Read More: CIP TCP/IP Interface Object Explained (Class 0xF5) »

RS-232 DB9 Pinout: Signal Reference, Wiring, and Field Troubleshooting

Most people land here for one thing: the pin numbers. That table is right below, so grab it and go if that’s all you need. The rest of the page is for when the table isn’t enough — when a link won’t talk, a device throws garbage, or you’re wiring two pieces of gear that were never meant… Read More: RS-232 DB9 Pinout: Signal Reference, Wiring, and Field Troubleshooting »

NERC CIP Compliance: Complete Guide to All CIP Standards

The North American power grid is the largest interconnected machine on the planet. A cyberattack that disrupts it does not just affect one company — it affects millions of people who depend on electricity for hospitals, water treatment, communications, and daily life. NERC CIP exists to prevent that. It is a set of mandatory cybersecurity standards that every… Read More: NERC CIP Compliance: Complete Guide to All CIP Standards »

CIP Connection Types Explained: Transport Class 0, 1, 2, and 3

Every CIP I/O connection has a transport class — a single nibble in the Forward_Open Transport Class Trigger byte that decides how the connection behaves. Class 0, Class 1, Class 2, Class 3 — engineers see these terms in Studio 5000, in Wireshark captures, in product documentation — but rarely with a clear explanation of what each one… Read More: CIP Connection Types Explained: Transport Class 0, 1, 2, and… »

CIP Identity Object Explained: How Every EtherNet/IP Device Identifies Itself

Every CIP device has one. Every browse of an EtherNet/IP network reads from it. Every Forward_Open validates against it. Every “what is this device” query touches it. The Identity Object (Class 0x01) is the most-accessed object on every CIP device — yet most articles barely cover it. This article fixes that. If you have ever wondered where Studio… Read More: CIP Identity Object Explained: How Every EtherNet/IP Device Identifies Itself »

EDS File Explained: CANopen and EtherNet/IP Device Files

An EDS file is a device’s résumé. It is plain text, it ships with the hardware, and your configuration software reads it so it does not have to know anything about your device in advance. Two industrial worlds use the same three letters for completely different files. CANopen has one EDS format. EtherNet/IP has another. They share an… Read More: EDS File Explained: CANopen and EtherNet/IP Device Files »

CIP Assembly Object Explained: How EtherNet/IP Devices Bundle I/O Data

When a ControlLogix PLC reads inputs from a 1734-AENT Point I/O block, it does not read each input one by one. It reads one big block of bytes that contains every input in a defined order. That block is an Assembly Object instance. The Assembly Object is the mechanism CIP uses to bundle scattered data — input bits,… Read More: CIP Assembly Object Explained: How EtherNet/IP Devices Bundle I/O Data »