ELS61-E: Hardware flow control CTS signal remains HIGH indefinitely | Telit Cinterion IoT Developer Community
August 10, 2020 - 2:54pm, 3192 views
Hi,
I'm using ELS61-E module to stream binary data using ASC0, 921600 baud with Hardware flow control enabled.
I use the transparent TCP service as explained in the Cinterion® ELS61-E2 documentation (10.15.10, page 6/08/2).
The CTS signal remains "LOW" as long as I have stable LTE connection, but when the connection is 2G/3G the signal goes "HIGH" and remains in this state indefinitely, evenif I stop streaming data and reset RTS signal.
any suggestions what the problem could be ?
The module I have is:
Cinterion
ELS61-E
REVISION 01.000
A-REVISION 00.026.00
Best regards,
kbehaimanot
Hello Tymoteusz,
I am using a PLS63W, however it seems that i am also struggling with serial buffer overflow. I am already using Hardware Flow Control to counter this, however i still get interface freeze. Is there any other way to do it?
Furthermore, how does the amount of data being transferred affect this?
kind regards,
Hello,
What is your scenario? Does the interface freeze forever? Does the module reply on USB?
The buffer would be filled when your application sends the data while the network connection throughput is not good enough to carry this. I would imagine that if the network connection still works, the data should be still accepted.
PLS63 is based on different chipset, so it should not necessarily behave exactly the same.
Can you check the firmware version with ATI1 command?
BR,
Bartłomiej
Hello,
I am sorry for taking that long to answer. I am trying to send files via Uart with a baudrate of 115200 with a size of around 90kB. Sometimes it works out and actually sends it without a problem. However, sometimes the CTS pin goes high and i cant send any other data. After a watchdog reset on the host it works fine again for a while. Sadly i dont have access to the USB interface. The firmware version on the chip is Cinterion_PLS63-W_REVISION01.002_A-REVISION01.000.07.
Even after 30 minutes it doesnt go high so i dont think that network throughput should be the problem. Could the serial buffer actually overflow eventhough we are using hardware flow control?
Hello,
How about switching from data to command mode? Didn't it help either?
As I see you have quite an old firmware version, one of the first public releases if not the first one. Don't you have any newer sample to try? I think that it is highly probable that there might have been some issue which was later improved. So, I would recommend you updating the module first. Please contact your distributor. It will be necessary to go through intermediate steps to get to the latest version possible.
Regards,
Bartłomiej
Good morning,
Do you mean switching when the CTS pin goes high? I can't send anything over UART if that happens. Before sending data I switch into transparent mode. Do I still have to switch into data mode before that?
Sadly I don't have access to a newer version. Is there an easy way to update the Firmware on the module?
Regards,
Bernhard
Hello,
I was just trying to figure out if switching to command mode is not possible in that situation that you have while CTS is high. Maybe toggling DTR line (if previously configured to to exit data mode if toggled) would work to switch back to command mode even if the buffer is full. Maybe it would not help if the buffer was still full. But is is always good to test.
You can update the firmware via USB or serial interface. You can use the standard gWinSwup Windows program that we provide with the firmware. In general the firmware updates can be found here: https://dz.telit.com/. But in case of your FW version you would first need to use the special intermediate firmware.
BR,
Bartłomiej