Hi,
There is a problem I have been dealing with for some time and I haven’t been able to found any solution yet. I have a POS computer, with OpenSUSE 12.3 installed. There is one COM port on the motherboard and I have an additional Axago serial port card with 2 ports inside the PC. The scanner which is attached to motherboard’s com port (ttyS0) is working just fine. I also have a scale attached to the PCI card (ttyS5 / ttyS6 - doesn’t matter) and this is where the problem comes in. In order to get the scale working, I have to weight the goods like 10x to get it working. These first 10 tries are getting timeout, and then the 11th try is successfull and the COM port is working all day brilliantly until the next PC restart.
By any chance, have some of you ever encountered this kind of behaviour ?
TL;DR - The COM port is working after 10th try and then it’s working all day.
The output of setserial is here:
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS4, UART: 16550A, Port: 0xec98, IRQ: 17
/dev/ttyS5, UART: 16650V2, Port: 0xdcf0, IRQ: 16
/dev/ttyS6, UART: 16650V2, Port: 0xdcf8, IRQ: 17
I haven’t experienced an issue like this, but I only ever use my USB-serial adapter for the occasional connectivity to a switch/router. Are you using XON/XOFF flow control? Are you using a cable with RX and TX lines for bi-directional communication?
How many bytes get sent for a typical weigh? I was just wondering if the 16550v2 FIFO buffer was impacting here somehow.
http://www.tldp.org/HOWTO/Serial-HOWTO-18.html#ss18.3
It might be useful to monitor the serial port (eg minicom) and watch the behaviour for the first X-number of weigh events…
Unfortunately and honestly I have no idea what are you talking about :\ That kind of knowledge is way beyond me.
Could you please give me a few minutes of your time and write the steps I should take ?
Thank you very much
I’m not sure how much help I can be here. This is a technical problem but an openSUSE-specific problem. You might want to share the POS package details and perhaps the make/model of the scales. Hopefully others that may be able to assist can also chime in here. I can only speculate as I have no idea about how the scales communication data/protocols might work. There are specialised forums (eg POS/scales/serial forums) that might be able to assist further.
Having said that, serial data is reasonably easy to capture, and minicom is a simple serial communications program that may help with the investigation here
Minicom how to…
https://help.ubuntu.com/community/Minicom
https://www.cyberciti.biz/tips/connect-soekris-single-board-computer-using-minicom.html
I’m assuming that it’s the POS software initiates the weigh request (with the appropriate serial characters)?.. and the scales then respond with scale data in some format.
On reflection I no longer think this is a hardware issue as such, but more likely a software specific configuration issue perhaps. While researching a little about scales and related software, I found this canscale page which described some typical configuration parameters used by software interacting with scales. In particular, it mentioned ‘Time out’ and ‘Delay after port close’ parameters which could be adjusted to cope with particular scale hardware. You haven’t yet shared the software package you’re using here, but you might want to check what configuration parameters are available within it (similar to the ScaleDisplay software page I linked to), or seek support from the developer if necessary.