Live List - HMS Anybus X-gateway Modbus-TCP User Manual

2.7 Live List

The live list features the possibility for Network 1 to continuously receive an I/O mapped list containing
the status of every transaction on Network 2. It is disabled by default, but can be enabled/disabled when
configuring the Modbus-TCP network settings. See "Modbus-TCP (Network 1 Server Interface)" on
page 35. If the live list is enabled, it will occupy either byte 0-7 (control/status word not enabled) or byte
2-9 (control/status word enabled and mapped to the first two bytes) in the input data area.
All transactions and their places in the live list are also visible in the Transaction Monitor on the config-
uration web pages.
The live list consists of a bit array with 64 elements, where each bit corresponds to a transaction on Net-
work 2 as in the table below.
Byte 7
Bit 63 Bit 62-56
Status of trans- Status of trans-
action no 63 action no 62-56
• Bit set to 1
Transaction successful.
• Bit set to 0
Transaction not successful.
The order of the transactions in the live list conforms to the order in which they are stored in the Mod-
bus Server list.
Example
Consider the following configuration:
• Server 1 : a total of 2 transactions
• Server 2 : a total of 3 transactions
• Server 3 : a total of 1 transaction
This scenario will produce a live list as follows (assuming that the transactions are successful):
Bit 63 Bit 62 - 6
- -
0 0
Note: Use the Modbus function "Read Discrete Inputs" to access the live list as a bit array.
Anybus X-gateway for Modbus-TCP - Modbus-TCP
Doc.Rev. 1.00
Byte 6-1 Byte 0
Bit 55-8 Bit 7
... Status of trans-
action no 7
Bit 5 Bit 4 Bit 3
Server 3, Server 2, Server 2,
transaction 1 transaction 3 transaction 2
1 1 1
Anybus X-gateway for Modbus-TCP - Modbus-TCP 14
Bit 6 - 2 Bit 1
Status of trans- Status of trans-
action no 6 - 2 action no 1
Bit 2 Bit 1
Server 2, Server 1,
transaction 1 transaction 2
1 1
Bit 0
Status of trans-
action no 0
Bit 0
Server 1,
transaction 1
1
Doc.Id. SCM-1200-114