M172* downloading application code faster

[obscuresc]

Hi,

I am developing an application on a TM172PDG18R.

Updating only the main application (~500KB, using the 'Download PLC Code' button) takes over a minute on Modbus TCP with a direct connection from my laptop. Downloading via Modbus via the USB Mini B port takes a similar amount of time.

Occasionally the PLC throws a watchdog 0 during this process.

What are the ways I can reduce the time it takes to download?

I am using a TM172PDG18R on BIOS 668p15, developing using ESME HVAC v1.7.0 and Windows 10 Pro 10.0.19045.

Thanks.

[M_Cervati · Accepted solution]

Hi,

this is the typical time to download. The strange event is watchdog 0 during application download.

Could you find a sequence of operation to reproduce sistematically this issue?

It could depend on the application (if target block sysWD_Background or sysWD_Timed are used under some condition), if you send me the project (by email marco.cervati@se.com) I can investigate about root cause.

Best regards

Marco Cervati   

[obscuresc]

Is there a way to speed up the download time?

The WDT0:0 occurs even if I have halted execution of the application prior to download, occurring at the end of the download, such that the last build console messages are

Spoiler

Verifying target compatibility
Unable to get info from target
Loading target image ..

Log of image upload.
Failed to get target info
failed.

I'm not using either of the watchdog functions.

I'll try putting a reproducible example together and email you.

Thanks!

[obscuresc · Accepted solution]

WDT0 in this case occurred because an array of pointers to status variables was being cleared to 0 during a partial download. The array is cleared even if no code accessing the array is executed, though there must be code present that does.

For example, in a background executed program;

Spoiler

IF (xExec) THEN;
xRet := Foo();
xExec := FALSE;
END_IF;

Where Foo() is

Spoiler

FUNCTION Foo: BOOL

VAR
diFaultCapacity : DINT := 0;
diNumRegisters : DINT := 0;
diNumFaultsInRegister : DINT := 0;
diBitIndex : DINT := 0;
diRegisterIndex : DINT := 0;
xRet : BOOL;
wRet : WORD := 0;
END_VAR

VAR_EXTERNAL
g_FaultStatus : ARRAY[0..5] OF @WORD;
END_VAR

pwTemp := g_FaultStatus[UINT#1];

If I download while xExec is False, the array is still cleared. I'm not sure on avoiding this issue. Ideally defining g_FaultStatus as CONSTANT would be allowed.

As for speeding up the download time, I have tried via RS485-1 with increased baud and using FTP (FileZilla). Both methods appear comparable. Manually having the application halted does not seem to increase the download speed.

I am not sure if disabling BACnet, HTTP server, or Modbus writes improve the transfer.

[FedericoM]

Hello,

I guess the update you made caused a cold/warn restart just after the download.

Have you tried to initialize the pointers in the init task?