S7+ Unknown error code -255

[andrek012]

Hello,

Using the S7+ driver and having about 270 PLC's connected (plan is to add another 220 PLC's), I do get the following messages quite often:

- SEVERE, 71/s7plus, GetVariablesCallbackHandler, error_get, Unknown error code -255 (-9129209860948427007)
- SEVERE, 71/s7plus, GetVariablesCallbackHandler, request_err, Unknown error code -102 (-6484601821636722790)

1) What does this mean? What is causing these messages?
2) How can the configuration be adapted such that these messages no longer occur (or occur less often)?

[dhoegerl]

Hello Mr. Keupers,

the first error code means some invalid internal variable address -> are you observing this error with some dedicated periphery address? Are you using the latest WinCC OA Patch? If so, can you provide us with your TIA Project or at least the export file?

The second error means "no connection" -> so either the communication layer S7DOS does not allow the connection (license? SIMATIC NET? Blank WinCC OA Installation or was there some other SIMATIC software installed before?) or there is some configuration problem with this PLC. What PLC type are you using?

Best regards,
Daniel

[andrek012]

I have attached the project file with the symbolic addresses for the S7 1200 PLC's we are using.

In total we have currently 268 S7 1200 PLC's connected (all using the same program logic).

We did previously use the S7 driver and now switched to the S7+ driver because it was not possible to connect more than 255 PLC's.

Is it possible that due to the first error, the connection is lost? https://www.winccoa.com/fileadmin/image ... ATX_V4.zip

[dhoegerl]

Do you get some log file error about the DPE address string that leads to the first error message? Or can you identify the causing address by activating them one by one?

Generally spoken: no. the first error cannot lead to connection loss. But do you have a valid license to run more than 64 connections? Your WinCC OA license should allow at least 512 connections in your case.

[andrek012]

Hello,

I first reduced from several hundreds of PLCs to just 3.

For each of them I get the same message (but without indication/hint of which address is causing the problem.

without any further hint where to start, I will have to (de)activate each address individually.

But I still hope you could give me a hint based on the project file and/or the attached log.

regards

André https://www.winccoa.com/fileadmin/image ... 7_log1.png

[dhoegerl]

Hello Andre!

The error from your latest log screenshot is new and tells us that the configured polling access cannot be handled by the PLC due to insufficient memory. This may come from reading large STRING arrays. Please check for them and change to reading single items of the array. In such case you may also want to consider using different pollgroups for reading all needed data.

Concerning your previous error message:
In your exported TIA project I don't see any general problem - lots of Bool/Byte/Int/String arrays but all of them are supported by the driver.

The only problem I can imagine concerns addresses that point to some other structure like:

00_Conf_data_PLC.Conf_Data.IP_V4.SubnetMask -> IP_V4
00_Timers.Req_SetIP -> IEC_TIMER
T_CONFIG_DB.Interface -> HW_INTERFACE

If you cannot find any address like those, you may try to set the transformation types of all periphery address configs to "Default" by setting _address.._datatype to 1001 using e.g. ASCII managers export/import and check the log for driver entries like "7/s7plus, Invalid transformation type 1001 in address ..."

Daniel

[andrek012]

In your first part you suggest to use different pollgroups. We use a single pollgroup and a single subscription for each PLC. furthermore all PLC's use the same subscription.

When I understand you right, the suggestion is to the single subscription into for example 6 different subscriptions (each used for a "logical" bock of data within the PLC). Each of these 6 subscrtions can refereto one and the same pollgroup (= frequency). Correct?

[dhoegerl]

Hello Andre!

I try to make it more clearly: The NotEnoughMemory error comes directly from the PLC (not the WinCC OA driver) and means that you somehow try to fetch too much data in a single attempt than the PLC can handle.

Please first check if you are reading some arrays large in size (e.g. STRING arrays) -> deactivate those address(es) and see if the error persists. If not, you should put those address(es) into another pollgroup.

Additional information to your subscription: The subscription will only work, if it can be activated on all PLCs, you configured it to use. You can check this by executing a "-report all" on the driver and looking at the "Subscription State" output for the particular subscription (pollgroup) -> value 3 means "active"; all other values indicate that all related address will not use subscription mode but rather be polled actively. In such case, activating the debug flag "subscr" at connection establishment (or driver startup) would give us more information about the reason.

Using subscriptions you even more have to consider PLC limitations. Take a look at the "Engineering" tab page of the S7+ driver configuration, where we summarize some basic information about the connected PLC: version, max. subscriptions and data values subscribable.

When switching to subscriptions completely, your first case of NotEnoughMemory error will probably lead to an error like the following, which also indicates that your configured addresses try to fetch too much data from the PLC:
Invalid value retrieved for subscription. Access denied = X, Out of memory = Y, Status = Z

Again to your original error message about the 270 PLC connections: you still haven't given us any information about your license!

[andrek012]

Hello,

Our license for S7+ = 512 (hence that part is OK).

We have discovered that from the 230 PLC, there are 43 which have the wrong version of software/logic (= still the old version for the previously used S7-driver - without the symbolic information included).
First we will upgrade these PLC's (and then most of the problems will be resolved).

The one problem remaining is the initial message that there is not enough memory (in the PLC). This is a little bit unexpected because I have split the data now into 7 different subscriptions (each containing less than 400 bytes).
However, except for this initial message everything seems to work (= we get regular updated values).

Is it possible that the S7+ driver combines all subscriptions into a single "request" upon Activation of the connection?

[dhoegerl]

Hello Andre,

in this case please send us the output of the "-report all" command on the driver and activate the "-dbg subscr" option on driver startup and send us the driver log file (WCCOAs7plus...log) after 30 seconds running, so we can help you analyse the subscriptions topic.

Nevertheless: the error message from your screenshot "There is not enough memory ..." does not come from some subscription but rather from a polling request!