Network Read/ Write TBL Definition

Byte Offset






D: Done (function complete)0 = not done1 = done

A: Active (function queued)0 = not active1 = active

E: Error0 = no error1 = error

Remote Station Address: address of the PLC where data is to be accessed

Pointer to data: an indirect pointer to the data in the PLC

Data Length: number of bytes of data to be accessed (1-16)

Receive or Transmit data area: 1-16 bytes (as specified in data length) reserved for the data, as described below.

For NETR, this data area is where the values read from the remote station are stored after execution of NETR.

For NETW, this data area is where the values to be sent to the remote station are stored before execution of the NETW.

Error Code


0 No error  
1 Timeout error; remote station not responding  
2 Receive error; parity, framing or checksum error in the response  
3 Offline error; collisions caused by duplicate station addresses or failed hardware  
4 Queue overflow error; more than 8 NETR/NETW boxes activated  
5 Protocol violation; attempted execution of NETR/NETW without enabling PPI+ in SMB30  
6 Illegal parameter; the NETR/NETW table contains an illegal or invalid value  
7 No resource; remote station busy (upload or download sequence in progress)  
8 Layer 7 error; application protocol violation  
9 Message error; wrong data address or incorrect data length