Network Protocol Reference
Explanation of function codes
Read Coil Status [01h]:
This function reads the status (ON/OFF) of selected coils. An example follows below.
•Read intelligent input terminals [1] to [6] of an inverter having a slave address “8.”
•This example assumes the intelligent input terminals have terminal states listed below.
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Intelligent input | [1] | [2] | [3] |
| [4] | [5] | [6] |
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Coil Status | ON | ON | ON |
| OFF | ON | OFF |
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Appendix B
Query:
No. | Field Name | Example | |
(Hex) | |||
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1 | Slave address *1 | 08 | |
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2 | Function code | 01 | |
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3 | Coil start number | 00 | |
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4 | Coil start number | 07 | |
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5 | Number of coils | 00 | |
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6 | Number of coils (low | 06 | |
| order) *2 |
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7 | 0D | ||
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8 | 50 | ||
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Response:
No. | Field Name | Example | ||
(Hex) | ||||
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1 | Slave address | 08 | ||
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2 | Function code | 01 | ||
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3 | Data size (in bytes) | 01 | ||
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4 | Coil data *3 | 17 | ||
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5 | (high order) | 12 | ||
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6 | (low order) | 1A | ||
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Note 3: Data is transferred by the specified number of data bytes (data size).
Note 1: Broadcasting is disabled.
Note 2: When 0 or more than 32 is specified as a number of coils, error code “03h” is returned.
•The data set in the response shows terminal states of coils 7 to 14.
•Data “17h = 00010111b” indicates the following assuming coil 7 is the LSB.
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| Coil Number | 14 | 13 | 12 | 11 |
| 10 | 9 | 8 | 7 |
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| Coil Status | OFF | OFF | OFF | ON |
| OFF | ON | ON | ON |
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