Alejandro Rueda
Mont Belvieu,TX
Summary
OT Cybersecurity and Industrial Controls Technician with 9 years of hands-on experience in instrumentation, SCADA communications, PLC/HMI systems, and securing industrial assets. Proven ability to harden ICS devices, resolve network misconfigurations, and support OT risk management and compliance initiatives. Skilled in diagnosing communication failures, improving system reliability, and maintaining secure configurations across PLCs, HMIs, radios, and IP-based cameras. Currently completing a Cybersecurity degree and focused on supporting OT cybersecurity programs in critical infrastructure environments.
Overview
10
10
years of professional experience
1
1
Certification
Work History
ICSR Custodian
Exxon Mobil
05.2024 - 12.2025
- Performed OT cybersecurity hardening on PLCs, HMIs, Radios, and field devices, including secure protocol configuration and disabling insecure services.
- Identified and resolved IP/MAC conflicts, network misconfigurations, and security deviations across multiple sites.
- Troubleshot SCADA communication issues involving radios, HMIs, PLCs, switches, and fiber links.
- Updated ICS inventories, including MAC addresses, firmware versions, IP tables, and topology notes.
- Supported OT security compliance by documenting findings, reporting risks, and coordinating remediation activities.
- Worked with SCADA, Automation, Cybersecurity, and operations teams to maintain secure and stable OT communications.
I&E Technician
Denbury Onshore
02.2021 - 05.2024
- Calibrated, tested, and repaired pressure, temperature, flow, and level transmitters and control valves.
- Diagnosed PLC and SCADA communication failures, including wiring issues, analog signal faults, and field equipment defects.
- Conducted loop checks, RTD module diagnostics, analog I/O verification, and panel troubleshooting.
- Supported MicroLogix and SCADAPack systems during field maintenance and upgrades.
- Provided detailed documentation and updates to SCADA and operations teams.
I&E Technician
Wunderlich-Malec
03.2020 - 01.2021
- Installed and commissioned instrumentation during industrial project builds.
- Performed loop checks, terminations, panel verification, and system startup troubleshooting.
- Calibrated and repaired transmitters, valves, and control components across multiple job sites.
I&E Technician
S&B Engineers and Constructors
05.2019 - 02.2020
- Supported instrumentation installation, testing, and commissioning during facility construction.
- DCS Marshalling Cabinet troubleshooting.
- Partnered with installer to troubleshoot and resolve instrumentation and electrical equipment and automation issues.
- Interpreted blueprints, schematics, drawings, and layouts to complete repairs.
I&E Technician
TASC
12.2018 - 05.2019
- Calibrated and repaired transmitters, valves, and control components across multiple job sites.
- Performed field repairs, transmitter calibration, and commissioning support for industrial facilities.
- Test SIS Systems.
I&E Technician
Ardent
04.2016 - 10.2018
- Calibrated and repaired transmitters, valves, and control components across multiple job sites.
- Supported instrumentation installation, testing, and commissioning during facility construction.
- Performed field repairs, transmitter calibration, and commissioning support for industrial facilities.
- Installed and commissioned instrumentation during industrial project builds.
Education
Master of Science - Cybersecurity
Lee College
Baytown, TX07-2026
Skills
- OT Cybersecurity & Compliance
- Hands-on hardening of PLCs, HMIs, radios, and networked OT devices
- Secure configuration of industrial protocols (Modbus, DF1, CIP, serial/IP interfaces)
- Removal/disablement of insecure services (SNMP, Telnet, FTP, HTTP)
- Updating passwords, credentials, and secure device strings
- Standardizing IP addressing, subnet corrections, and secure network paths
- Supporting compliance programs (ICSR, OT security initiatives) ICS / SCADA Systems
- PLCs: Allen-Bradley MicroLogix 1100/1400, SCADAPack 350
- HMIs: PanelView Plus 600/700/1000
- SCADA: CygNet (poll diagnostics, comms troubleshooting)
- I/O systems: analog modules, RTD modules, control circuits Communications & Networking
- Radios: XetaWave Xeta9, FreeWave FGR2/FGR3
- Radio configuration: IP lists, routing paths, port assignments
- Fiber media converters and Ethernet troubleshooting
- Subnetting, IPv4 addressing, gateway and routing diagnostics
- Troubleshooting packet loss, latency, and polling interruptions Video Surveillance & OT Camera Systems
- Installation, configuration, and troubleshooting of industrial IP cameras
- PoE injector and switch diagnostics (Moxa, unmanaged PoE equipment)
- Cable terminations, testing, and replacement
- Review of camera risk assessments and supporting OT security requirements Software & Tools
- RSLogix 500 / RSLinx Classic
- Telepace Studio
- FactoryTalk View Studio
- HART communicator, loop calibrator
- Red Hat Linux (lab), Kali Linux basics
- Microsoft Office Suite
Certification
- TestOut PC Pro
- TestOut Security Pro
- TestOut Server Pro 2016: Identity
Timeline
ICSR Custodian
Exxon Mobil
05.2024 - 12.2025
I&E Technician
Denbury Onshore
02.2021 - 05.2024
I&E Technician
Wunderlich-Malec
03.2020 - 01.2021
I&E Technician
S&B Engineers and Constructors
05.2019 - 02.2020
I&E Technician
TASC
12.2018 - 05.2019
I&E Technician
Ardent
04.2016 - 10.2018
Master of Science - Cybersecurity
Lee College