MBS Protocol
PLX30 Series
User Manual
Ethernet and Serial Gateways
Page 134 of 200
ProSoft Technology, Inc.
September 19, 2012
7.3
MBS Diagnostics
7.3.1 PCB Diagnostics
The best way to troubleshoot the MBS driver is to use ProSoft Configuration
Builder to access the diagnostic capabilities of the gateway through the Ethernet
debug port. For instructions on how to access
Diagnostics
Diagnostics in ProSoft Configuration Builder
(page 36).
7.3.2 MBS Status Data in Upper Memory
Each Modbus port has an associated status data area located in the
gateway’s
upper memory. The Data Map functionality of the gateway can be used to map
this data into the normal user data range of the gateway
(page 27).
General Modbus Error and Status Data
The following table lists the starting addresses in upper memory where general
error and status data for each Modbus Master or slave port can be found.
Modbus Port
Starting Address
1
4400
2*
4800
3*
5200
4*
5600
*Status data for Ports 2 through 4 is only present in 4-port MBS gateways.
Note:
None of the addresses are available in the Modbus address range. In order for them to be
accessed via a Modbus request, they must be moved into the 0 to 3999 address range. See
(page 27).
The status data area is initialized with zeros whenever the gateway is restarted.
This occurs during a cold-start (power-on), reset (reset push-button pressed) or a
warm-boot operation (commanded from a debug screen or after downloading a
new configuration).
