Product Overview

The CTI 901C-2599​ is an AC discrete output module from the CTI 2500 Series Classic I/O family, built by Control Technology Inc. for plants running CTI 2500 Series or legacy Siemens SIMATIC 505 (originally Texas Instruments TI 505) programmable controllers. Its job is straightforward but essential: it takes low-level logic commands from the PLC backplane and uses solid-state switching to turn externally supplied AC power on and off, driving pilot lamps, solenoids, contactors and motor starters in the field.Where legacy 505 AC output cards are now difficult to source, the CTI 901C-2599​ is the drop-in answer. It is designed as a direct functional and form-factor replacement for Siemens 505-4608, -4616, -4632, -4808, -4816 and -4832 modules, fitting the same I/O base without rewiring and without re-addressing the I/O. The module can be logged in as 8, 16 or 32 output points, so the same part number covers several densities, and it switches an unusually wide 11 to 240 VAC range at up to 2.0 A per point.Electrically, the CTI 901C-2599​ is built around sourcing solid-state outputs with individually fused channels, 3000 VDC isolation between groups and 2100 VDC isolation from the output channels to the backplane. That combination — solid-state switching with no mechanical contacts to wear, per-point fusing so one short does not take down a whole group, and heavy isolation to suppress ground loops and common-mode noise — is exactly what keeps ageing 505 installations running reliably in electrically noisy process environments. For maintenance teams, the CTI 901C-2599​ is one of the highest-value spares on the shelf, because a single failed output card can stop a production line that is otherwise perfectly serviceable.

Technical Specifications

Main Features and Advantages

Wide voltage range that simplifies spares: The CTI 901C-2599​ switches anything from 11 to 240 VAC, so the same module serves 24 VAC indicator circuits, 120 VAC solenoid and contactor coils, and 230 VAC loads found on European-designed machines. Instead of stocking separate cards for each voltage, a plant can standardise on one part number and reduce both inventory cost and the risk of fitting the wrong card during an outage.Configurable point density: Logged in as 8, 16 or 32 points, the CTI 901C-2599​ adapts to the addressing scheme already configured in the CPU. That flexibility means one spare covers the output variants originally supplied as 505-4608, -4616 or -4632, which is a real advantage when you are maintaining a site with mixed racks and incomplete documentation.Solid-state switching for long service life: Because the CTI 901C-2599​ uses solid-state output circuits rather than electromechanical relays, there are no contacts to pit, weld or wear out. In applications with frequent cycling — packaging machines, sequencing valves, alarm annunciators — this translates directly into longer intervals between failures and no contact-life budgeting.Per-point fusing that contains faults: Each output on the CTI 901C-2599​ is individually fused. A shorted solenoid or a damaged cable takes out one fuse and one channel, not an entire group of eight, so the maintenance call becomes a fuse replacement during a short intervention rather than a card swap and a re-test of thirty-two points.Isolation built for noisy plants: With 3000 VDC between groups and 2100 VDC from channels to backplane, the CTI 901C-2599​ holds up in the electrically hostile cabinets typical of chemical, power and water treatment sites, where ground loops and common-mode interference are routine. Combined with a single-wide footprint that consumes only one slot, a removable 40-pin connector for fast field wiring, and optional conformal coating for humidity and contamination, the CTI 901C-2599​ is a practical, low-risk way to keep a legacy 505 or 2500 Series installation in service for years beyond its originally planned life.