The 1747-PIC - A well driven soul...
GaryS said:
No the PIC cable has been obsolete for about 10 years now. I think they stopped using about the same time XP came out. I still have one. you could only use it on a real com port and the RSLinx driver would only allow you to select com 1 or 2 and it only worked with the SCL line of processors if I remember the processor connection was DH485...
The 1747-UIC was released in 2003.
Why?
Well, for a couple of reasons...
Rockwell knew that an imminent trend in the computer manufacturing world at that time was to begin slowly phasing out the RS-232 9-pin serial port on most of their computer offerings. Both Desktop and Portable. USB was fast becoming the new serial port for all computer peripheral devices. This trend started in 2004 and the slow decline continued up to around the 2009 mark, where ever since, only a select few models, from a select few manufacturers, provide this hardware feature, natively.
Lenovo, whom we use for our leased business computers, currently offer no serial port models. There isn't a CD/DVD drive either on my current model, for that matter, but that's a whole other story of declination.
Toshiba stopped providing serial ports after 2010, with only a serial port replicator option available. I used one on my last business laptop - did not work so well.
Dell have also gone the way of replication for their once serially endowed Latitude Series. They now only offer built in serial ports on their Rugged Series. The 12" have one, the 14" have two, no less. But you pay a handsome price for such a luxury.
Fujitsu is another manufacturer that I know of that provides a serial port option. Mid 2014 they launched two models for their LIFEBOOK E Series. I remember because I looked into them before buying the second HP. For their E554/J model, a serial port is available as an optional extra.
HP, from whom I have two programming laptops, provide one on the ProBook 6560b (older model) and the EliteBook 8570p (newer model). There are others too, but the model numbers are not to hand.
I'm not sure about other manufacturers, but from what I know, HP seem to me to be the best well known brand which still provide native serial support on their not too expensive laptops?
Anyhow, I'm rambling...
So Rockwell released the UIC, in part, to counteract this impending hardware revolution. But also, they released it to finally do away with the myriad of driver issues they had long since lived with for the 1747-PIC.
The PIC interface was introduced way back in 1990 along with the SLC Family of Controllers. It was a DOS based interface device. It originally used WinLinx (RSLinx predecessor) to communicate. It had all the necessary resources available to its limited comms buffer. This worked well until Microsoft got clever and started overlaying DOS with a GUI. The newer Windows based OS (3.x) began "managing" resources and the new, but limited, "COMM.DRV" driver was introduced. Soon, the PIC was starved of its high speed connection resources. The DOS based device could not cope within this new "let's share" environment.
The COMM driver had to regularly switch over and back between real and protected mode, so this made it far too unreliable at high speed communications. Many companies had to rewrite the COMM driver as it was too slow for their serial devices' requirements.
ICOM, the original authors of WinLinx, rewrote the Windows serial port COMM driver to hand back the necessary resources to the PIC. I remember you had to edit the system.ini file "COMM.DRV=RHSICOM.DRV" to use the modified driver. So all was well again.
That was until Windows 95 arrived on the scene. Native DOS was all but dead now. It brought with it a whole new suite of communications improvements and enhancements. Remember all that email, fax, and online services that was starting to creep in. So again, ICOM (now Rockwell owned) had to set about rewriting the Windows 95 drivers. But this proved much more difficult with so many changes to the communications architecture and subsystem. It took many attempts before they finally released a relatively stable version. But the DOS based PIC still was not out of the oh so foreign woods just yet. Some of the communication enhancements that Windows 95 introduced also hindered the PIC. The VCOMM virtual comm port driver, that was supposed not to interfere with it's partner in the real world, did just that, on occasions. Also, newer power management options would tickle the com port periodically to see if it was awake, interrupting current transmissions through the PIC. Serial mouse drivers would now auto load on Windows startup for "convenience" should you require them, locking the serial port out from the PIC, and on and on.
But did they give up?
Where's the fun in that?...
Next there was the huge hurdle of the Hardware Abstraction Layer (HAL - "
Just what do you think you're doing, Dave?") that was introduced with Windows NT. Applications and device drivers were now no longer allowed to deal with hardware directly and had to make calls to HAL routines to determine hardware specific information. This added back in unacceptable latency for the PIC's limited comms buffer. So once again, a lengthy journey was undertaken to rewrite NT's COMM driver. Even so, it had headaches. HAL must prime its routines during POST, so that meant the modified driver had to be loaded at BOOT. Making it unloadable until REBOOT. So once finished with the PIC, you had to REBOOT to free the COM port up for other applications.
Then came along Windows 2000 with a much improved HAL, yippee!...and yet again, the drawing board had to be wiped clean.
Eventually, Windows XP came on the scene and things became somewhat easier. There was little change with regard to the HAL and the PIC would work reasonably well. One advantage was that now you only had to delete the driver in Device Manager to free up the COM port, rather than have to REBOOT.
But the party was short lived. This hiatus lasted until Windows XP SP3 was released and the Serial Enumerator handler was updated, again making the PIC an outcast. "Serenum.sys" is an upper-level device filter driver that is used with a serial port function driver, namely "Serial.sys", to enumerate devices that are connected to a serial port. "Serial.sys" is the default provided function driver for serial devices, but any third party serial driver can be used in conjunction with Serenum.sys. The updates included changes in how the enumerator mapped COM ports to devices.
At last, a hurdle too high...
Between the protection issues instigated by Windows File Protection, which restores any modified protected system files, and the fact that the method used to mitigate said protection i.e. the replacing of Serenum.sys with the XP SP2 version, renders the serial port useless to all applications, but the PIC Driver - Rockwell threw in the towel and no longer pursued the, up until then, crazy, but somewhat commendable, path to keeping the 1747-PIC alive.
However, while the 1747-UIC might have appeared to be the direct successor to the 1747-PIC interface, this was not entirely the case. They both had there uses and relevance, at that time. Only computers running at or above Windows 95 circa 1998 supported USB v1.1 devices, which the UIC happens to be. Many 9-pin serial port only computers were still available to purchase and indeed in service running under older OS. So before, and indeed after Windows XP was released, the PIC was/is still required to support legacy computers that do not support USB. They could not, and did not "
stop using (the PIC) about the same time XP came out". In fact, the 1747-PIC did not reach its Silver Series Date until 7/1/2008. Some seven years after Windows XP was first released.
God rest its well "driven" soul.
Regards,
George