IEC60870-103 Unable to read analog measures

[steven.costantini]

Hi,
i have a big problem.
I want to read three analog measures from a protection using iec870-103 protocol via serial communication.
Zenon has a IEC870-103 driver correctly configured: it can read variables states from protection.
My problem come when i want to read Voltage, Current and Power measures.
I configured variables as follows:


Current: FUN: 160 INF: 144 INDEX: 0
Voltage: FUN: 160 INF: 145 INDEX: 1
Power: FUN: 160 INF: 146 INDEX: 2

I inserted in a page three Zenon Numeric Values object to display values of the variables. I see 0 value in each analog variables. Using an analog reaction matrix I understood that BL_870 bit is active for the three analog variables.
You can say me there is a reading-block in the protection (BL_870 bit) but using a simulator, problem doesn't appear.

Using a master simulator of IEC870-103 protocol, three analog values are correctly red.

Which is my mistake?
Why simulator works and Zenon doesn't work?
It depends on time sinc?

Help me please.

Steven Costantini.

[steven.costantini]

Hi,
i have a big problem.
I want to read three analog measures from a protection using iec870-103 protocol via serial communication.
Zenon has a IEC870-103 driver correctly configured: it can read variables states from protection.
My problem come when i want to read Voltage, Current and Power measures.
I configured variables as follows:


Current: FUN: 160 INF: 144 INDEX: 0
Voltage: FUN: 160 INF: 145 INDEX: 1
Power: FUN: 160 INF: 146 INDEX: 2

I inserted in a page three Zenon Numeric Values object to display values of the variables. I see 0 value in each analog variables. Using an analog reaction matrix I understood that BL_870 bit is active for the three analog variables.
You can say me there is a reading-block in the protection (BL_870 bit) but using a simulator, problem doesn't appear.

Using a master simulator of IEC870-103 protocol, three analog values are correctly red.

Which is my mistake?
Why simulator works and Zenon doesn't work?
It depends on time sinc?

Help me please.

Steven Costantini.

Variables are configured as MONITORING, type: REAL. I want to highlight using a master simulator, analog values are correctly read.

[ursulak]

Are you sure that you see status bit BL_870? Maybe rather SB_870?

You can easy see the status bits of zenon variable also without ReMa if you right click on screen element where variable is linked or in 'Variable diagnosis' screen - column 'status'.

The SB_870 bit will mean that the protection device does not respond these variable in GI (general interrogation request). For Measurands nothing strange, the Standard defines that GI may does not contain IOs with INF <144>..<148>.

So the interesting question would be: when value changes in protection - is the SB bit in zenon still set? If then not set anymore but value still 0.0 - probably variable range settings are wrong (e.g. PLC range differs adjusted range, or missing digits). Please note that MEA is according the Standard a normalized value - has range [-1..1>. So set property 'digits' > 0.

[steven.costantini]

Are you sure that you see status bit BL_870? Maybe rather SB_870?

You can easy see the status bits of zenon variable also without ReMa if you right click on screen element where variable is linked or in 'Variable diagnosis' screen - column 'status'.

The SB_870 bit will mean that the protection device does not respond these variable in GI (general interrogation request). For Measurands nothing strange, the Standard defines that GI may does not contain IOs with INF <144>..<148>.

So the interesting question would be: when value changes in protection - is the SB bit in zenon still set? If then not set anymore but value still 0.0 - probably variable range settings are wrong (e.g. PLC range differs adjusted range, or missing digits). Please note that MEA is according the Standard a normalized value - has range [-1..1>. So set property 'digits' > 0.

I understood measures are not sent during General Interrogation. Currently I'm not sure information I give you regarding BL_870 and SB_870 are right, bypass these for the moment.
In Zenon I declare three variables as in the print screen in attachment (current (corrente in italian), voltage (tensione in italian), power (potenza in italian). I can't understand why all variables in zenon are 0 valued, unsing a simulator variables are set correctly.

In Zenon property (as you can see in attachment adjusting_three_variables.png), all three variables has range [-32768, +32767]. Maybe my mistake is here.

[ursulak]

You see 0, but maybe it is 0.498?

Please set variable property 'Digits' (Italian: 'Calcolo valore' - 'Cifre decimali') to value bigger 0, e.g. 3.
The range you may expect on MEA is -1.000 to 0.999, not bigger. For MEA your RTU is for sure using some multiply factor - to convert values to this range before it sends it to the Master (zenon). So you have to use also the same multiplying factor to display values received from RTU.

[ursulak]

One more question: are you sure that the Net Address (Italian: 'Indirizzo di rete/buss') is 0?
It should be the same as in the driver configuration the Net Address of the connection.

[steven.costantini]

One more question: are you sure that the Net Address (Italian: 'Indirizzo di rete/buss') is 0?
It should be the same as in the driver configuration the Net Address of the connection.

Yes, i'm sure. I've only one connection in driver configuration with net address 0.

[steven.costantini]

Hi,
I want to underlight that using a master simulator, I could observe that variables already contain scaled value (not in range -1, +1), consider that I must multiply for 2.4 to obtain correcly measure.
So Zenon should read exactly the same values red by my simulator.

[ursulak]

Unfortunately the multiply factor is not defined in the Standard, so we cannot relay on some fix value. I know devices using other factors.

If this factor is fix in the device then in zenon you may define the factor 2.4 by configuring 'value adjustment linear'; -2.4 .. 2.4 (while 'signal range' is -1.0 .. 1.0). The best practice would be to create in zenon Editor an additional data type - inherited from REAL - with updated settings for 'digits' and for 'value adjustment'. Then you may simply link to normalized MEA variables your own, smarter data type (instead type REAL).

[steven.costantini]

Unfortunately the multiply factor is not defined in the Standard, so we cannot relay on some fix value. I know devices using other factors.

If this factor is fix in the device then in zenon you may define the factor 2.4 by configuring 'value adjustment linear'; -2.4 .. 2.4 (while 'signal range' is -1.0 .. 1.0). The best practice would be to create in zenon Editor an additional data type - inherited from REAL - with updated settings for 'digits' and for 'value adjustment'. Then you may simply link to normalized MEA variables your own, smarter data type (instead type REAL).

Thank you for your replies. Tomorrow I will test another time the system and verify what you told me.
Another question: if I created variable with range -38000, + 38000, I will expect that Zenon reads in some way values from my protection, greater then zero, not zero fixed.