Application Scenarios
Picture a water-pumping station where the only interaction the operator ever needs is acknowledge, scroll, and start pump two. The panel is twenty-five metres from the wet well, the air is damp, the screen is small and the DH+ link has been stable since the plant opened. Then the function-key membrane starts double-striking and the overlay cracks along the F3 edge.
Ordering a touchscreen HMI would be solving the wrong problem. A 2711-T9A1 swap keeps the 9-inch cutout, the 100–240 VAC supply, the DH+ addressing and the whole PanelBuilder 32 project exactly as they are. The operator presses F3 the same way at the next shift change, and the only thing anyone notices is that the key finally clicks again.
Parameter
| Main Parameters | Value / Description |
|---|---|
| Product Model | 2711-T9A1 |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Product Category | PanelView 900 operator terminal, keypad-only, monochrome STN |
| Display | 9.0 in monochrome supertwist STN LCD, 600 × 300 pixels, high-contrast FSTN-type characters |
| Viewable Area | approx. 183 × 92 mm (7.2 × 3.6 in) — a wide, shallow working area, shaped for lists and tags rather than graphics |
| Pixel / Character Pitch | 0.30 × 0.30 mm; character cell 5 × 7 dot matrix |
| Display Technology | High-contrast STN, 3 or 4 grey levels, cold-cathode backlight (CCFL) with 3-level brightness control |
| Operator Input | 21 relegendable function keys (F1–F20) + cursor pad; optional external keyboard via the accessory port |
| Function-Key Life | 1 million presses per key — the part of the terminal that usually outlasts the membrane overlay |
| Application Memory | 2 MB, split 1 MB SRAM + 512 KB flash + 512 KB EEPROM (battery-backed); project stored as .PBA runtime |
| Real-Time Clock | Battery-backed calendar/clock with daylight saving; battery (1747-BA / similar) field-replaceable |
| Communications | 2 × 9-pin D-sub: DH+ (primary, for PLC-5/SLC 500), DF1 full-duplex or half-duplex / ASCII on the secondary; also DH-485 capable in the family |
| Network Throughput | DH+ 57.6 kbit/s typ.; DF1 half-duplex up to 19.2 kbit/s — adequate for tag updates, not bulk data |
| Software | PanelBuilder 32, versions 3.4 through 3.8x; runtime is the .PBA application, not a .MER |
| Power Input | 100–240 VAC, 50/60 Hz (catalogue “A” = AC terminal) |
| Power Draw | 30 VA typical, 40 VA max — a fraction of a PanelView Plus, which is why these still sit in 30-year-old panels |
| Backlight Life | CCFL, 50,000 hour design life at 25 °C; dimming the third level materially extends it |
| Front Protection | NEMA Type 12, 13 and 4X indoor; IEC IP65 front face, IP54 rear |
| Environment | 0 to +55 °C operating, 5–95% RH non-condensing, up to 2,000 m altitude |
| Form Factor | Panel-mount, approx. 279 × 171 × 84 mm; cutout 254 × 146 mm (10.0 × 5.75 in), 2.3–2.5 kg |
| Approvals | UL 508, CSA, CE, FM Class I Division 2, Australian compliance |
| Lifecycle | Discontinued (PanelView Standard family end-of-life); supported through repair, exchange and migration |
Technical Principles and Innovative Values
Innovation Point 1 — The display is deliberately not a graphics canvas. At 600 × 300, the 2711-T9A1 was never trying to be a picture. It is a tag-and-list machine: alarm summaries, setpoint tables, manual-control lines and a cursor that moves through them. That constraint is why a 2 MB memory budget was enough to run a whole pump station’s interface for fifteen years, and why the screen stays legible under a sodium lamp at midnight.
Innovation Point 2 — Two serial ports, two different jobs. The primary 9-pin carries DH+, Rockwell’s token-passing link that lets the terminal sit as just another node on the same blue cable as the PLC-5. The secondary port runs DF1 full-duplex, half-duplex or ASCII, which is how you hang a barcode reader, a serial printer for alarm logs or a dumb terminal. On a 2711-T9A1 the DH+ network never has to be repurposed as a printer cable — a small detail that prevents a lot of late-night wiring confusion.
Innovation Point 3 — Keypad-first ergonomics in a world that forgot them. Every function key is a physical, relegendable button with a tactile click and a 1-million-press rating. For a washdown panel, a gloved hand or an operator who is supposed to keep eyes on the machine, that beats a soft button on glass. The membrane overlay is the consumable, not the terminal, and it is replaceable separately.
Innovation Point 4 — Battery-backed non-volatile context. The 1 MB SRAM plus flash/EEPROM split means the alarm history, the recipe and the RTC survive a power blip, while the replaceable lithium cell keeps the clock honest. In a plant where the monthly report is printed from the terminal’s own log, that battery is a maintenance item with a real deadline.
Innovation Point 5 — The cutout that outlived the product. The 254 × 146 mm opening is shared across the PanelView 900 family and carries forward into the PanelView Plus 6 900. Fit a 2711-T9A1 today as a like-for-like repair, or use the same hole for a modern touch terminal later. Either way the panel door does not change, and that is the difference between a 30-minute repair and a sheet-metal job.
Application Cases and Industry Value
Case 1 — Steel pickling line, PLC-5 DH+ cell. The line’s original HMI was a 2711-T9A1 mounted beside the acid-tank walkway: F1 through F8 stepped the line speed, the cursor pad selected the strand, and the alarm list was the only thing the rollers looked at. After years of mist and heat, the F5 membrane tore and the backlight went moody, so the crew started reaching through the guard to the local pushbutton station — exactly the bypass the safety review had spent years eliminating. A like-for-like 2711-T9A1 exchange, a new relegendable overlay and a backlight assembly restored the intended interface inside a single planned stop. The DH+ node number, the .PBA application and the PLC-5 logic were untouched. The win was not the new screen; it was that the operators stopped treating the guard as part of the control panel.
Case 2 — Package sewer lift station, remote site. A small station used a 2711-T9A1 as the local face of an SLC 500, with DH+ to the processor and the secondary port feeding a serial alarm printer. The terminal’s 30 VA appetite meant the whole HMI rode on the same AC run as the controls with headroom to spare, and the monochrome display stayed readable in full sun through a south-facing window. When the backlight began taking five minutes to strike on cold mornings, the maintenance team fitted a backlight assembly and recalibrated nothing — there is no touch to calibrate on a keypad terminal. Alarm timestamps stayed aligned because the RTC battery had been swapped on schedule. The station kept its local interface for another four years while the migration to a PanelView Plus 6 900 was planned around a single outage, not forced by one.
Related Product Combination Solutions
| Model | Synergy with 2711-T9A1 |
|---|---|
| 2711-T9C1 / 2711-T9C3 | Colour PanelView 900 siblings (C-series, same 9 in cutout). Move here when the operators need colour alarm states but you want to keep the keypad and the DH+ wiring. |
| 2711-K9A1 | Keypad-plus-touch variant of the 900 class. Use it when a few soft-screen areas would help but the hard keys must stay. |
| 2711-T5A1 / 2711-T5C1 | 5.5 in PanelView 550 family. The compact fallback when a 9 in opening is being downsized or a smaller door is being fabricated. |
| 2711P-T6C5A / 2711P-T6C20D8 | PanelView Plus 6 600 (5.7–5.8 in) and Plus 7 600. The migration step up: modern runtime, Ethernet/IP, same general door geometry story for a planned upgrade. |
| 2711P-T9C4A8 / 2711P-T9C4D8 | PanelView Plus 6 900, the natural Rockwell-successor family: 9.4 in colour TFT, touch, Ethernet + serial, same 254 × 146 mm cutout, AC or DC supply. |
| 2711P-T9C22D8S / 2711P-T9C22D9P | PanelView Plus 7 Standard and Performance 900. The current-platform destination when the DH+ link can finally be retired for EtherNet/IP. |
| 1747-KE / 1770-KF2 / 1784-PCMK | DH+ couplers, protocol converters and the PCMK card. They are the reason a 2711-T9A1 can still be programmed and diagnosed from a modern laptop, and the first tools to reach for when the DH+ link looks dead. |
| 1747-BA | 3 V lithium clock battery for the SLC/PanelView generation. Cheap, shelf-stable, and the only thing between your alarm log and a clock that resets to the factory date. |
| PanelBuilder 32 v3.8x + 1747-PIC | The software and PIC programming cable that actually move a .PBA onto a 2711-T9A1. Note the cable choice: the 9-pin DF1 path is not the same animal as a PIC-to-DH+ path, and using the wrong one is the classic “cable is fine, must be the terminal” misdiagnosis. |
Installation, Maintenance, and Full-Cycle Support
Installation is a panel, a supply and a port-check job. Confirm the opening is 254 × 146 mm and that you have the AC terminal — the “A” in 2711-T9A1 means 100–240 VAC, so do not drop it into a 24 VDC panel without a proper AC run and fusing. Isolate the supply at the disconnect and wait a moment for the CCFL inverter to discharge. Remove the four clamp screws from the rear, support the terminal from the front (it is heavy for its size at roughly 2.4 kg), label the two 9-pin cables before unplugging them, and note which is DH+ and which is DF1/ASCII. Refit the new unit, tighten the clamp ring only until the gasket seals evenly, then restore the ports. On first power-up, verify the terminal reads its own application revision on the status line, then check the DH+ node LED and the PLC-5’s I/O table before you hand it back to operations.
Maintenance is almost entirely the overlay and the battery. Wipe the screen and keys with a damp soft cloth and a mild detergent; never let liquid run along the membrane seam and never use solvents on the relegendable key labels — they lift, and a lifted label is how a wrong setpoint gets pressed. Dim the backlight to the middle level when the panel is in a lit room; it is the single biggest factor in backlight life. Once a quarter, confirm the RTC against the control-room clock and order a 1747-BA at the first sign of drift. Once a year, exercise every function key and compare the on-screen response with the legend strip — a key that double-strikes is a membrane on its way out, and replacing the overlay is cheaper than explaining to an operator why F4 is really F3. Keep the latest .PBA and a printed legend map in the CMMS; when the terminal is swapped, the application and the labels are the only two things that must travel with it.
Support that understands what “legacy” actually costs. The 2711-T9A1 has been out of catalogue for years, so a supplier’s job is no longer to read you a datasheet — it is to ship a terminal that boots your .PBA, holds DH+ at 57.6 kbit/s against a real PLC-5, and has a backlight and keypad matrix that will not fail on the night shift. Every unit we release is powered through POST, both 9-pin ports are loop-tested under DF1 and DH+ traffic, the keypad matrix is checked key by key, the backlight uniformity is measured across all three levels and the RTC is set and allowed to run for a soak period before dispatch. We confirm the series letter and the AC/DC suffix against your label photo, because a 2711-T9A1 and its DC sibling share a face but not a supply. If repair is the smarter call — overlay, backlight or battery rather than a whole terminal — we will say so and return your original legend set with it. If migration is due, we will flag which DH+ objects have no direct Ethernet equivalent and which alarm screens will need a rebuild in FactoryTalk View ME before the new terminal goes in.
Contact us for a customized solution — send a photo of the 2711-T9A1 label, the two connector cables and the key legend strip, and we will confirm the exact variant, the DH+ node setup and whether you need a like-for-like swap, a repair, or a PanelView Plus 6 900 migration before the next shutdown.
