YASKAWA SI-P3/V Technical Manual page 23

Handshaking Register
Handshaking is used to synchronize the timing of the sending or receiving of MEMOBUS/Modbus message data
between the SI-P3/V unit and the PROFIBUS-DP master.
When the master toggles bit 7 of the handshaking register in the output data, the SI-P3/V starts to process the data in the
MEMOBUS/Modbus registers. Ensure that the data in the MEMOBUS/Modbus registers is valid before toggling bit 7.
When the SI-P3/V toggles bit 7 of the handshaking register in the input data to the same value as the handshaking register
bit 7 in the output data, the content of the input data MEMOBUS/Modbus registers is valid.
Handshaking Output Register
PROFIBUS-DP Master to SI-P3/V Unit
Bit 7 6 5 4
HS – – –
Bit Name
7 HS
1 to 6 –
0 INIT
Handshaking Input Register
SI-P3/V Unit to PROFIBUS-DP Master
Bit 7 6 5 4
HS STATUS
Bit Name
7 HS
5 to 6 STATUS
<1>
1 to 4 WD
<1>
0 –
<1> STATUS and WD are for reference.
YASKAWA ELECTRIC SIEP C730600 23B V1000 Option PROFIBUS-DP Technical Manual
3 2 1 0
– – – INIT
• Handshaking bit. Synchronizes send and receive timing. Changes status when sending new command
messages
• This bit is reset to 0 at power up or by setting the handshaking output register bit INIT to 1
Reserved
Clears the handshaking bit to 0
3 2 1 0
WD –
• Handshaking bit. Synchronizes send and receive timing. Changes status when sending new command
messages.
• This bit is reset to 0 at power up or by initializing the handshaking output register bit INIT back to 0.
Status of the data exchange between the PROFIBUS-DP master and the drive.
00H: Idle
01H: SI-P3/V sends a MEMOBUS/Modbus command to the drives.
10H: SI-P3/V waits for a MEMOBUS/Modbus response from the drives.
11H: SI-P3/V receives a MEMOBUS/Modbus response from the drives.
Counter increases every 64 ms
Reserved
7 Conventional Formats
Function
Function
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