Purchase now: Allen Bradley 1747-R21 Keypad Overlay
Purchase now: Atlantechdrives provides you the 1747-R21, a highly specialized replacement keypad overlay designed by Allen Bradley exclusively for the legacy 1747-PT1 Hand-Held Terminal (HHT). In the early days of the SLC 500 platform (specifically targeting the Fixed Hardware, SLC 5/01, and 5/02 processors), before the widespread adoption of engineering laptops and RSLogix software, technicians relied entirely on the 1747-PT1 HHT to program ladder logic, configure communication parameters, and perform offline diagnostics. The 1747-R21 is the English-language membrane keypad overlay that adheres directly to the front of this terminal. Over years of grueling factory floor use, original membrane keypads become cracked, unresponsive, or illegible due to chemical exposure, UV light fading, and heavy mechanical pressing. Replacing the damaged skin with the pristine 1747-R21 restores the physical interface of your legacy programming tool, ensuring you can still support your older control panels.
Technical Specifications of the 1747-R21
This overlay features an industrial-grade adhesive backing and raised, tactile domes over the key contact points to provide positive mechanical feedback to the user.
- Part Number: 1747-R21
- Component Type: Hand-Held Terminal Keypad Overlay
- Language: English
- Compatible Hardware: 1747-PT1 Hand-Held Programmer
- Compatible Processors: SLC 5/01, SLC 5/02 (via HHT)
- Material: Industrial-grade polycarbonate membrane skin
- Function: Restores tactile button response and visual legibility
Maintenance: Restoring Your Hand-Held Terminal
If you are still maintaining legacy SLC 500 systems, a functional HHT is an invaluable backup tool when a laptop is unavailable or a communication cable fails. Maintenance Tip: The membrane keypad overlay is composed of multiple layers, including a graphical top layer that resists factory lubricants, and a conductive trace layer that registers the keystrokes. When peeling off the old overlay, technicians must be incredibly careful not to damage the underlying printed circuit board (PCB) of the hand-held terminal. Utilizing a plastic spudger and an ESD-safe workspace is highly recommended. You must meticulously clean the underlying plastic chassis with 99% isopropyl alcohol. Any remaining adhesive residue or factory dust trapped under the new 1747-R21 overlay will create «dead spots» where the keys will not register a press.
Expert Advice: ZIF Connector Alignment
Ensure the delicate ribbon cable tail of the new overlay is seated perfectly into the zero-insertion-force (ZIF) connector on the HHT motherboard before you peel the backing off and seal the adhesive. If the tail is inserted at an angle, entire rows or columns of the keypad will fail to function. Because the 1747-PT1 is completely dependent on this membrane for input, a failed keypad renders the entire diagnostic tool useless. The 1747-R21 is a cost-effective maintenance item that prevents you from having to source a completely new programmer on the surplus market.
Frequently Asked Questions (FAQs)
Q: Does the 1747-R21 include the actual electronic programming terminal?
A: No. The 1747-R21 is strictly the replacement membrane keypad overlay (the physical sticker with the tactile buttons). It does not include the 1747-PT1 terminal screen, chassis, or internal electronics.
Q: Can I use this keypad to program an SLC 5/04 or 5/05?
A: The 1747-PT1 Hand-Held Terminal is primarily designed for the fixed controllers and the early SLC 5/01 and 5/02 processors via DH-485. Later processors (5/03 and up) require RSLogix 500 software on a PC.
Do you need more references from this brand? Explore our full catalog of Allen Bradley here.
For reliable relay switching in high-vibration environments, ensure your system uses a robust 1746-OW16 relay output module.
