Rockwell Automation 1395 Node Adapter Board - Manual (Page 23)

Chapter 3
Functional Description
3-11
Node Adapter Status Byte
The Node Adapter Status Byte is returned from the Node Adapter Board in
addition to the Block Transfer Status Byte (Word 4, high byte). The Node
Adapter Status Byte appears as the upper byte in the PLC Controller input
image table of the first slot associated with the rack. This status byte
indicates the condition of the Node Adapter Board itself and is not part of
the standard block transfer blocks in the PLC Controller program.
Figure 3.6 details the information contained in this byte. Individual bits
from this byte are used in the PLC Controller program to control the block
transfer functions (refer to the block transfer examples).
Figure 3.6
Node Adapter Status Byte
17 16 15 14 13 12 11 10
Block Transfer Ready (BT _ READY)
Block Transfer Write in Progress (BT_ WR_IPROG)
Block Transfer Read AVAIL (BT_RD_DATA_AVAIL)
Block Transfer Wait (BT_WAIT)
Block Transfer Error (BT_ ERROR)
Reserved for Future Expansion
Reserved for Future Expansion
Reserved for Future Expansion
Bit
Block Transfer Ready – Indicates that the drive and Node Adapter Board are communicating
(via the Microbus) correctly. If the bit is set, the Bulletin 1395 is ready to process and receive
block transfer requests.
IMPORTANT: Do Not attempt to send block transfers if this bit is not set. The drive will not
respond to the request.
Block Transfer In Progress – Is set when a write block transfer to the Node Adapter Board is in
progress. This bit remains set until the message has been received and placed in the queued
message buffer of the drive.
IMPORTANT: Do Not attempt to initiate another block transfer when this bit is set. The drive will
not respond to the request.
Block Transfer Read Data Available – Is set when the drive has data available which the PLC
could read.
Block Transfer Wait (Message Being Processed) – Indicates that a message has been sent to
the drive via the queued message mechanism and is awaiting a response. This bit is set at the
completion of the write block transfer and is cleared at the reception of the response (start of the
Read Block Transfer Request).
Block Transfer Request Error – When set, the Node Adapter Board has received an incorrect
block transfer request from the PLC. This bit will be cleared when a correct block transfer has
occurred.
BIT
10
11
12
13
14