Specifications

GWY-01-DNT-01 MANUAL – REV. 02 CHAPTER 5:
DEVICENET INTERFACE
PAGE 55 OF 67
3. Following execution of the command, the Gateway writes its response to the
Input Controller Tag, starting with the 2-byte Produce Data Size, at
Local:2:I.Data [2] and the actual data beginning at Local:2:I.Data [3]. It then
increments the counter value at Local:2:I.Data [1]. This alerts the PLC to the
new data available (the Gateway generated response, in this case).
4. After processing the response information, the PLC copies the counter from
Local:2:I.Data [1] to Local:2:O.Data [0], which signals to the Gateway that the
PLC has retrieved the response data.
OUTPUT CONTROLLER TAG
CONTROLLER TAG
LOCATION AND DATA
DESCRIPTION
Local:2:O.Data [0]
(4) The PLC copies the value at 2:I:Data[1] here to
acknowledge receipt of the response
Local:2:O.Data [1] (1) The PLC increments this counter value after copying
a command in Consume Data
Local:2:O.Data [2]
Consume Data Size
Local:2:O.Data [3]
First WORD of Consume Data (Command from PLC)
Local:2:O.Data [xxx]
xxx WORD of Consume Data
INPUT CONTROLLER TAG
CONTROLLER TAG
LOCATION AND DATA
DESCRIPTION
Local:2:I.Data [0] (2) The value at 2:O:Data[1] is copied here by the
Gateway to acknowledge receipt of a command
Local:2:I.Data [1]
(3) The Gateway increments this counter to signal that a
response is available
Local:2:I.Data [2]
Produce Data Size
Local:2:I.Data [3]
First WORD of Produce Data (Response from Gateway)
Local:2:I.Data [xxx]
xxx WORD of Produce Data
NOTE: A ladder logic example illustrating the implementation of this handshaking
strategy can be downloaded from the technical support area of the EMS website.