Issue with COM port (LPT1-parallel)
jerome037
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brucine Posted messages 24411 Registration date Status Membre Last intervention -
brucine Posted messages 24411 Registration date Status Membre Last intervention -
Hello everyone.
I’m having a problem with a DB25 to USB cable (the cable used to connect a parallel printer) LPT1.
When I plug my cable into a USB port on one of my PCs (Windows 20 or seven), the drivers install correctly. When I go to the device manager, then to the COM port tab, I don't see the port that should be called "LPT1" (or 2, or 3... it doesn't matter). I know the drivers are installed because the cable is recognized in the device manager (under the USB bus control tab, I see the USB print manager line show up when I plug in the cable and it disappears when I unplug it).
The problem I am encountering:
I need an LPT port because I use a programming interface that requires a serial port and an LPT port (I have no issues with the serial port!).
When I launch my software, adjusting the ports, I can change the port number in the serial port, but in: LPT port, I have nothing offered since it doesn’t appear in the device manager.
I’ve tried installing drivers, doing updates, uninstalling... nothing works.
If you have any ideas or help to offer, I would be grateful :)
Thank you!
I’m having a problem with a DB25 to USB cable (the cable used to connect a parallel printer) LPT1.
When I plug my cable into a USB port on one of my PCs (Windows 20 or seven), the drivers install correctly. When I go to the device manager, then to the COM port tab, I don't see the port that should be called "LPT1" (or 2, or 3... it doesn't matter). I know the drivers are installed because the cable is recognized in the device manager (under the USB bus control tab, I see the USB print manager line show up when I plug in the cable and it disappears when I unplug it).
The problem I am encountering:
I need an LPT port because I use a programming interface that requires a serial port and an LPT port (I have no issues with the serial port!).
When I launch my software, adjusting the ports, I can change the port number in the serial port, but in: LPT port, I have nothing offered since it doesn’t appear in the device manager.
I’ve tried installing drivers, doing updates, uninstalling... nothing works.
If you have any ideas or help to offer, I would be grateful :)
Thank you!
2 réponses
Good evening,
In the meantime, which should not take long, until a more competent speaker takes over, here are a few elements, which will be completed or contradicted.
The USB port corresponds to one of the serial ports (COMx).
The adapter you are using converts the signals from the USB output into signals transmitted over 8 wires of the parallel connector.
This can only be done if the installed driver is compatible with the version of Windows installed.
We need to be sure that the driver supplied with this device is qualified for the recent versions of Windows. Nothing is less certain, especially if you are on a 64-bit configuration.
My suggestion would be to install your hardware (machine and USB/parallel port adapter) on a PC running XP or Vista (32-bit) to check what it is, even if it means dedicating a machine to your work, knowing that the support, and thus the safety and operation of this machine, is highly discouraged under external connection (internet).
In the meantime, which should not take long, until a more competent speaker takes over, here are a few elements, which will be completed or contradicted.
The USB port corresponds to one of the serial ports (COMx).
The adapter you are using converts the signals from the USB output into signals transmitted over 8 wires of the parallel connector.
This can only be done if the installed driver is compatible with the version of Windows installed.
We need to be sure that the driver supplied with this device is qualified for the recent versions of Windows. Nothing is less certain, especially if you are on a 64-bit configuration.
My suggestion would be to install your hardware (machine and USB/parallel port adapter) on a PC running XP or Vista (32-bit) to check what it is, even if it means dedicating a machine to your work, knowing that the support, and thus the safety and operation of this machine, is highly discouraged under external connection (internet).
Hello,
Thank you for your response. Regarding the installation on XP, that is not possible; the software only works starting from Windows 7.
As for the DB25 > USB cable drivers, the drivers are okay up to Windows 11 (confirmed by the manufacturer). The cable comes from a well-known manufacturer, namely StarTech.
https://www.startech.com/fr-fr/cartes-additionelles-et-peripheriques/icusb1284d25
One weird thing:
I have an HP laptop running Windows 7 64-bit with a docking station underneath. On this docking station (which I believe is called a dock?), there is a recognized LPT1 port. When we bought this laptop, the station was provided with it, software installed and everything, so the LPT1 port was already set up.
To explain in more detail, my aim is to no longer use this docking station because I am constantly on the move and it must be powered with the laptop charger, which is often complicated or even impossible for me, hence the desire to use a DB9 > USB and DB25 > USB cable.
Yo
Thank you for your response. Regarding the installation on XP, that is not possible; the software only works starting from Windows 7.
As for the DB25 > USB cable drivers, the drivers are okay up to Windows 11 (confirmed by the manufacturer). The cable comes from a well-known manufacturer, namely StarTech.
https://www.startech.com/fr-fr/cartes-additionelles-et-peripheriques/icusb1284d25
One weird thing:
I have an HP laptop running Windows 7 64-bit with a docking station underneath. On this docking station (which I believe is called a dock?), there is a recognized LPT1 port. When we bought this laptop, the station was provided with it, software installed and everything, so the LPT1 port was already set up.
To explain in more detail, my aim is to no longer use this docking station because I am constantly on the move and it must be powered with the laptop charger, which is often complicated or even impossible for me, hence the desire to use a DB9 > USB and DB25 > USB cable.
Yo
The OS won't change anything since there is no physical parallel port and using a mixed cable isn't enough to fool the enemy.
If we're dealing with a tower and not a laptop, the best solution is of course to install a parallel PCI card, provided there is a free slot available.
If not, the possible solution depends on the software being used; in a recent topic, there was talk of printing under Dos to a USB printer, which is contradictory but can be achieved through dedicated utilities.
The same type of solution may exist to "emulate" a parallel port from a USB port.
For this purpose, do a Google search such as "emulate (or 'simulate') parallel port on usb."
https://superuser.com/questions/182655/how-do-i-simulate-a-parallel-lpt-printer-with-a-usb-printer