If you're in search of a 1784-T45 Portable Terminal from Allen Bradley, you might be interested to know that I have access to one that is not for sale. This particular unit operates on DOS and features the '6200 Programming Software.' It is capable of interfacing with PLC-2, PLC-3, and PLC-5 models. The terminal is equipped with a 3.5-inch floppy disk drive, and it utilizes cable 1784-CP 96746402 for connecting to a PLC-5, which is still actively in use. The reason this terminal won’t be available for purchase is due to its ongoing functionality in operational settings.
In the past, during my time with an Allen-Bradley distributor, we had a few vintage "programming terminals" stored on the top shelf. Occasionally, we would loan them out to customers facing urgent needs, typically once or twice a year. If you're in good standing with your local representatives, it's worth reaching out to them for assistance. Best of luck with your project!
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- 05-03-2025
- JohnCalderwood
Strantor mentioned: "On another note, if anyone has a prepared speech for 'The Big Letdown'—where you need to inform a customer that their valuable equipment has officially reached the end of its life—I would gladly accept that."
To share my perspective, I believe we must confront this issue directly. I recently faced a similar situation involving relatively new hardware. At one client's facility I visited, a lightning strike caused significant damage. Fortunately, a Mitsubishi PLC survived because it was powered by a 24V DC power supply, while the 240VAC/24VDC power supply failed instead of the PLC itself.
Conversely, a Micrologix 1500 PLC that had 240VAC connected to its base unit unfortunately did not fare as well and was rendered inoperable. It’s worth noting that these units are no longer manufactured, making it impossible for us to source replacements from our distributor. Although we could have explored options on eBay or similar platforms, my manager decided that the only solution we could offer was a new PLC (Micrologix 1400), which the customer readily accepted—his urgency to get the machine operational was quite high.
Ian
The PLC-3 features an RS232 serial port specifically designed for programming, utilizing a 25-pin DIN connector located on the front of the processor. To establish a connection, I employ a 9-pin to 25-pin null modem cable. This versatile controller can be configured to support up to four Remote I/O devices, four Data Highway connections, or a combination of both. To check the channel configuration, it's necessary to go online. It's worth noting that the original programming terminal lacks the capability to upload and save programs, as it was intended solely for online programming. Historically, these programs were saved using a tape deck. For programming with Allen-Bradley PLC, it is important to remember that the software operates exclusively in a DOS environment or on a virtual machine (VM) simulating DOS. Good luck with your projects!
Gary is absolutely correct; I was incorrectly recalling aspects of the unusual port associated with the PLC-2. We consistently utilized the 1771-KE interface to establish a connection with these controllers. The PLC-3, on the other hand, is a robust system, even for those accustomed to the earlier models. In situations where a facility has lost its programming and engineering tools, there’s a significant risk of not having the necessary program backups. Thus, the request to "simply load the PLC" can quickly escalate to "spending several weeks to get the control system operational." Best of luck!
GaryS mentioned that the PLC-3 features an RS232 serial port designed for programming, accessible via a 25-pin DIN connector located at the front of the processor. To connect, I typically use a 9-pin to 25-pin null modem cable. Additionally, this PLC model supports configuration for up to four Remote I/O modules, four Data Highway connections, or any combination of both. To view and adjust the channel configuration settings, you need to go online. It's worth noting that the original programming terminal lacks the capability to upload or save programs, as it is intended solely for online programming—historically, programs were saved using a tape deck. Good luck with your project! Keep in mind that the AB PLC software operates exclusively in DOS or a virtual machine simulating a DOS environment.
Also, is it possible to access channel configurations through the front panel keypad and display? It would also be helpful to determine if there’s an available mode switch on the device.
This client must act swiftly to replace their PLC-3 with a modern alternative. The last time I encountered a PLC-3 was approximately 15 years ago, discarded in the dumpsters behind the Rockwell office located north of Detroit.
In my area, there are still a few PLC-3 controllers in operation that I'm aware of. One was retired during the closure and decommissioning of a local paper mill, where it had been pushed beyond its intended service life due to the mill’s eventual shutdown. Another PLC-3 is actively functioning in a larger, more advanced mill that has opted to transition all PLC-3 functionalities to their expanding DeltaV DCS. However, this upgrade is at least a decade behind schedule, and I'm not the one who advocated for the switch to DeltaV. Additionally, a PLC-3 is in use at Johnston Atoll within a closed-loop incinerator system. If you’re searching for parts on eBay, make sure to have a Geiger counter handy!
Reflecting on my experience, it seems that Allen-Bradley (AB) didn't support the PLC-3 for an extended period. Our local distributor advised us against it, leading us to transition directly from the PLC-2 to the PLC-5 series. This switch highlights the importance of choosing the right programmable logic controller (PLC) for industrial automation.
The local Allen-Bradley office in Northern California previously had a T-45 terminal, which was utilized to extract programs from PLC-3 controllers for the few remaining users in the area. Due to liability concerns, they were unable to provide repair or reprogramming services. The only option available was to hire their Service Technicians to retrieve the programs as part of the upgrade process to a Logix platform. It’s advisable to reach out to the Allen-Bradley office in Houston to inquire whether they still offer this service for PLC-3 program extraction.
Due to liability concerns, they refused to "fix" or reprogram the devices. I really wish GTS had advocated for me during that situation. It was dangerously frustrating trying to stay alert while driving 400 miles for the PLC-3 assignment, only to have another job lined up the very next day. This experience ultimately led me to resign.
I still proudly hold my initial A-B training certification, obtained in 1984 for the PLC-3 system. At that time, the PLC-3 was the industry standard in automotive paint manufacturing, featuring a robust hot backup and bubble memory technology. Over the span of a couple of years, I dedicated my efforts to integrating A-B's RFID technology into PLC-3 systems, managing a significant amount of data—10,000 words across 10,000 distinct files. It was a monumental undertaking!
Wow, I’m genuinely surprised by the number of responses this thread has received! I had a chance to glance at a few before I headed out this morning. I truly appreciate all the assistance!
**Update:** It turns out the PLC lost its memory, a fact I confirmed by navigating through the front panel keypad and display. Interestingly, they had a backup program stored on a CD from 2006, which was the last time anyone accessed it—this coincided with the CPU batteries' timeline.
The PLC serves as the central command and control hub for a ship loading dock, networking with at least 25 PLC5 units in various configurations. Connected to the system are two vintage XP desktops functioning as Human-Machine Interfaces (HMIs) running RSView. They utilize a DH+ PCI card linking to a KF2 box, which communicates back to the PLC3. Both machines are quite antiquated and are equipped with floppy drives, making them ideal candidates for online programming; however, neither possesses a DOS dual-boot option or the necessary programming software.
Together with a few colleagues from the IT department, I spent the day sifting through dusty old computer components and files, hoping to locate the elusive software. Apparently, it once resided on a machine that may or may not have last been spotted under someone’s desk around 2010. We also scoured for blank floppy disks and a USB floppy drive—it felt like an exhilarating treasure hunt!
I managed to download DOS, transfer it to floppy disks, and found an old IDE hard drive to install it on. Despite encountering numerous errors due to utilizing 25-year-old floppy disks, after several attempts, I successfully installed DOS. I found Ai3 on the floppies and managed to get it installed, but with no master disk or activation key, I could only access the "AB3" program, which kept flagging the activation issue.
To my dismay, I discovered that the program was written for the 6200-PLC3 rather than Ai3. I continued my search for the required software and eventually installed 6200-PLC5, but unfortunately, it was incompatible with the PLC-3 I was working with.
I left the site without resolving the issue, which is frustrating. I felt like I had thoroughly exhausted every possible avenue. Fortunately, there’s someone coming in tomorrow who created the backup in 2006 and still possesses the original software. They’ve invited me back to work alongside him, and I’m looking forward to learning more about their system, even though I’m uncertain about our collaboration dynamic. It seems they may be considering me as a potential troubleshoot expert for this aging setup, and I’m conflicted about that role.
Thank you for the comprehensive update! It exceeded my expectations! Upgrading and migrating large systems is both thrilling and demanding. In contrast, hospice care for aging controllers lacks that same level of excitement.
It's been some time since I've worked with DH+, which is essentially a fieldbus protocol. Is it possible to download a program from the old desktop using the current setup via the KF2 box? I suspect that might not be feasible, but I wanted to check. That would be a simple solution. I assume I'll need to connect a serial cable to the DB9 port on the PLC for direct communication?
Ken Roach expressed his gratitude for the comprehensive update, noting, "It exceeded my expectations!" He highlighted that upgrading and migrating large systems can be both thrilling and demanding, while acknowledging that providing hospice care for aging controllers is far less engaging.
He went on to emphasize that updates and migrations are unavoidable. In fact, he suggested inviting a competitor to submit a bid for the project. "At this moment, I'm unable to commit to a project of this magnitude due to my current workload," he stated, referring to his numerous ongoing obligations. However, he expressed his willingness to consider bidding again if the project's circumstances remain unchanged in six months.
If anyone possesses the AI3 or 6200-PLC software and is open to sharing a copy, I would greatly appreciate it. I believe my request is legitimate, as one of these software programs was originally offered for free, while the other is no longer available for purchase. It's likely that both have expired their copyright by now. I'm eager to explore these tools for my projects!
The 6200-PLC3 software was never genuinely "free"; it was simply unprotected by copy safeguards and became a target for widespread piracy. Both software packages remain under copyright protection; in the United States, a work created for hire is protected for 95 years from its initial publication. In practical terms, Rockwell Automation typically does not take action against copyright infringements concerning unsupported software. I believe that any upgrades to the PLC-3 should be handled by companies with existing expertise and resources, or through collaboration with these firms. This approach will position you as the "local expert"— equipped with a deep understanding of the installation process and plant operations, making you a trusted resource for customers over the next 25 years.
Ken Roach stated that the 6200-PLC3 software was never truly "free"; rather, it lacked copy protection and was frequently pirated. Both software packages remain under copyright protection; in the United States, the copyright for a work created for hire lasts for 95 years post-publication. In practice, Rockwell Automation does not actively pursue copyright infringement for unsupported software. Thank you for sharing this information; I wasn’t aware of it.
Roach further expressed his belief that PLC-3 upgrades should be handled by firms with the necessary experience and tools, or through collaboration with these firms. This partnership allows individuals to become the "local expert," possessing thorough knowledge of the installation process and plant operations—ensuring that customers can depend on their expertise for the next 25 years.
I concur with his viewpoint. When I approached my first project, I wasn’t adequately prepared. Stepping in without prior knowledge would have likely led to more complications than solutions. What you suggested aligns with our current approach. Just yesterday, I spent the day on-site with a Rockwell technician who has been maintaining this PLC for over 23 years. He taught me the essential processes and insights I needed. I sensed his relief in passing the torch; he’s now focusing on larger engineering projects valued in the millions, and I can imagine that returning to this task feels tedious for him.
The issue has been resolved, and neither of us will be returning to that particular site. However, I’m concerned about future support. I currently lack access to the necessary software, and unless I can track it down, he’ll be the designated expert every time. He mentioned that he would be happy to share the software with me, but unfortunately, he no longer has the physical disks; the software resides solely on his two-decade-old Windows 98 local machine.