ADVANCED FUNCTIONS
STATUS CODES The status codes are described in the following table.
Code | Error | Description |
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|
|
0x00 | Number of | |
|
| |
|
|
|
0x01 | Single node missing | Slave address of the missing node. Reports if a node is |
|
| missing |
|
|
|
0x02 | Multiple nodes | Number of missing nodes. Reports if multiple nodes are |
| missing | missing |
|
|
|
0x03 | Overrun | Slave address of the node that sent too much data. |
|
| Reports if more data than expected was received from a |
|
| node |
|
|
|
0x04 | Other error | Slave address. Reports unidentified node |
|
|
|
0x1F | No error | Normal Condition |
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|
|
HANDSHAKING The handshake bits are used to indicate any changes in the status and control registers. PROCEDURE The procedure below must be followed for all changes to these registers with the exception
of the handshake bits themselves (bits 14 and 15).
Status Register Reads | Control Register Writes |
Start | Start |
Compare CR_HS_CONFIRM with SR_HS_SEND
Equal?
Yes
Compare SR_HS_CONFIRM with CR_HS_SEND
Equal?
No
No
Yes
Read Status Register
Write to Control Register
Set CR_HS_CONFIRM to SR_HS_SEND
End
Toggle CR_HS_SEND
End
Figure 8-1: Handshaking flowchart
P485 MODBUS TO PROFIBUS CONVERTER – USER GUIDE |
