Response message to C_RD_NA_1 request not defined in standard

[EdwinKielSMA]

I'm devoping a IEC60870-5-104 server using this library and testing it with the WinPP104 program.
When reading a point by the C_RD_NA_1 command I get the following sequence:

2026-04-21 10:50:37,983 - journalLogger - INFO - Receive: 680d00000000660105000000030101 I-Format | C_RD_NA_1 | REQUEST | POSITIVE | CA 0 | 1st IOA 65795 | LIST[1] (03 01 01 )

1. 2026-04-21 10:50:38,031 - journalLogger - INFO - Transmit: 680d00000200660107000000030101 I-Format | C_RD_NA_1 | ACTIVATION_CON | POSITIVE | CA 0 | 1st IOA 65795 | LIST[1] (03 01 01 )
2. 2026-04-21 10:50:38,031 - journalLogger - INFO - Transmit: 6819020002002401050000000301010000c841005f94320a15041a I-Format | M_ME_TF_1 | REQUEST | POSITIVE | CA 0 | 1st IOA 65795 | LIST[1] (03 01 01 00 00 c8 41 00 5f 94 32 0a 15 04 1a )

The server is after receiving the C_RD_NA_1 request 1. sending a C_RD_NA_1 message with CoT ACTIVATION_CON and POSITIVE. Then 2. the message M_ME_TF_1 with the point and its value to be read is transmitted.

The WinPP104 program remarks that the 1. message has a wrong CoT. Looking into the standard (Druckfreigabe DIN EN 60870-5-101) my understanding is that this 1. message is not required (only in cases when the addressed point is not available) and that sending the 2. message with M_ME_TF_1 alone would be sufficient.

My questions:

• is my understanding of the standard correct
• can the behavior of the library configured anyway for this (the handling of C_RD_NA_1 is within the libary)?
• or is this maybe a bug?