---
title: "IEC 104 Client | Appendix | N3uron KB V1.22"
slug: "iec-104-client-appendix"
description: "IEC 104 Client allows to quickly and easily connect to any IEDs, RTUs,  controllers, and gateways that adhere to the IEC 60870-5-104 protocol."
updated: 2025-09-30T15:55:30Z
published: 2025-12-22T18:13:11Z
canonical: "docs.n3uron.com/iec-104-client-appendix"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.n3uron.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Appendix

## Supported ASDUs

| Type | Description | Reference | Format | Valid COTs |
| --- | --- | --- | --- | --- |
| Process information in monitor direction |
| 1 | Single point information | M_SP_NA_1 | SIQ | 2,3,5,11,20,20+G |
| 2 | Single point information with time tag | M_SP_TA_1 | SIQ + CP24Time2a | 3,5,11,12 |
| 3 | Double point information | M_DP_NA_1 | DIQ | 2,3,5,11,12,20,20+G |
| 4 | Double point information with time tag | M_DP_TA_1 | DIQ + CP24Time2a | 3,5,11,12 |
| 5 | Step position information | M_ST_NA_1 | VTI + QDS | 2,3,5,11,12,20,20+G |
| 6 | Step position information with time tag | M_ST_TA_1 | VTI + QDS + CP24Time2a | 2,3,5,11,12 |
| 7 | Bit string of 32bit | M_BO_NA_1 | BSI + QDS | 2,3,5,11,12,20,20+G |
| 8 | Bit string of 32bit with time tag | M_BO_TA_1 | BSI + QDS + CP24Time2a | 3,5 |
| 9 | Measured value, normalized value | M_ME_NA_1 | NVA + QDS | 2,3,5,11,12,20,20+G |
| 10 | Measured value, normalized value with time tag | M_ME_TA_1 | NVA + QDS + CP24Time2a | 3,5 |
| 11 | Measured value, scaled value | M_ME_NB_1 | SVA + QDS | 2,3,5,11,12,20,20+G |
| 12 | Measured value, scaled value with time tag | M_ME_TB_1 | SVA + QDS + CP24Time2a | 3,5 |
| 13 | Measured value, short floating point value | M_ME_NC_1 | IEEE STD 754 + QDS | 2,3,5,11,12,20,20+G |
| 14 | Measured value, short floating point value with time tag | M_ME_TC_1 | IEEE STD 754 + QDS + CP24Time2a | 2,3,5,11,12,20,20+G |
| 21 | Measured value, normalized value without quality descriptor | M_ME_ND_1 | NVA | 1,2,3,5,11,12,20,20+G |
| Process telegrams with long time tag (7 octets ) |
| 30 | Single point information with time tag CP56Time2a | M_SP_TB_1 | SIQ + CP56Time2a | 3,5,11,12 |
| 31 | Double point information with time tag CP56Time2a | M_DP_TB_1 | DIQ + CP56Time2a | 3,5,11,12 |
| 32 | Step position information with time tag CP56Time2a | M_ST_TB_1 | VTI + QDS + CP56Time2a | 2,3,5,11,12 |
| 33 | Bit string of 32bit with time tag CP56Time2a | M_BO_TB_1 | BSI + QDS + CP56Time2a | 3,5 |
| 34 | Measured value, normalized value with time tag CP56Time2a | M_ME_TD_1 | NVA + QDS + CP56Time2a | 3,5 |
| 35 | Measured value, scaled value with time tag CP56Time2a | M_ME_TE_1 | SVA + QDS + CP56Time2a | 3,5 |
| 36 | Measured value, short floating point value with time tag CP56Time2a | M_ME_TF_1 | IEEE STD 754 + QDS + CP56Time2a | 2,3,5,11,12,20,20+G |
| Process information in control direction |
| 45 | Single command | C_SC_NA_1 | SCO | 6,7,8,9,10,44,45,46,47 |
| 46 | Double command | C_DC_NA_1 | DCO | 6,7,8,9,10,44,45,46,47 |
| 48 | Setpoint command, normalized value | C_SE_NA_1 | NVA + QOS | 6,7,8,9,10,44,45,46,47 |
| 49 | Setpoint command, scaled value | C_SE_NA_1 | SVA + QOS | 6,7,8,9,10,44,45,46,47 |
| 50 | Setpoint command, short floating point value | C_SE_NC_1 | IEEE STD 754 + QOS | 6,7,8,9,10,44,45,46,47 |
| 51 | Bit string 32bit | C_BO_NA_1 | BSI | 6,7,8,9,10,44,45,46,47 |
| System information in control direction |
| 100 | General Interrogation command | C_IC_NA_1 | QOI | 6,7,8,9,10,44,45,46,47 |

## Information Elements

| Element Type | Description |
| --- | --- |
| SIQ | Single-point information with quality descriptor |
| DIQ | Double-point information with quality descriptor |
| BSI | Binary state information |
| QDS | Quality descriptor |
| VTI | Value with transient state indication |
| NVA | Normalized value |
| SVA | Scaled value |
| IEEE STD 754 | Short floating point number |
| SCO | Single command |
| DCO | Double command |
| QOS | Qualifier of set-point command |
| QOI | Qualifier of interrogation |
| CP24Time2a | Three-octet binary time |
| CP56Time2a | Seven-octet binary time |