Yaskawa VS-616G5 Profibus-DP Control Card SI-P - Manual (Page 15)

VS-616G5 Option Instruction Manual: Profibus-DP Control Card SI-P Page 15
Handshaking Register
The handshaking protocol is used synchronises the MODBUS data exchange between the
Profibus-DP master and the option card. The handshaking protocol is simple to use and
implement in a PLC program. One register (byte 31) in the input and output area is dedicated
to this protocol.
HANDSHAKE OUTPUT REGISTER
PDP Master
⇒ G5 SI-P option card
HANDSHAKE INPUT REGISTER
G5 SI-P option card
⇒ PDP Master
* The STATUS and WD bits give additional information about the option card. The
user does not have to access or use these bytes in the PLC program to exchange data
using MODBUS messages.
b7 b0
HS - - - - - - INIT
Bit Name Function
7 HS Handshaking bit. Used to synchronize the data exchange. Tog-
gled when a new command is transmitted.
NOTE: This bit must be cleared after power-up or reinitializa-
tion by the PLC program.
6 - 1 — Not used
0 INIT Used for reinitialization of the handshaking protocol
b7 b0
HS STATUS WD -
Bit Name Function
7 HS Handshaking bit. Used to synchronize the data exchange. Toggled
when a new response is transmitted.
6 - 5 STATUS * Status of data exchange between option card and inverter.
00H: Idle
01H: Sending MODBUS command to inverter
10H: Waiting for MODBUS response
11H: Response received
4 - 1 WD * Counter incremented approximately each 64ms.
0 — Not used