Operating instructions

Reference PTQ-MCM ♦ Quantum / Unity Platform
Modbus Communication Module
ProSoft Technology, Inc. Page 125 of 139
April 29, 2008
Code Name Meaning
08 Memory Parity Error
Specialized use in conjunction with function codes 20 and
21 and reference type 6, to indicate that the extended file
area failed to pass a consistency check. The server (or
slave) attempted to read record file, but detected a parity
error in the memory. The client (or master) can retry the
request, but service may be required on the server (or
slave) device.
0a
Gateway Path
Unavailable
Specialized use in conjunction with gateways, indicates
that the gateway was unable to allocate an internal
communication path from the input port to the output port
for processing the request. Usually means that the
gateway is misconfigured or overloaded.
0b
Gateway Target Device
Failed To Respond
Specialized use in conjunction with gateways, indicates
that no response was obtained from the target device.
Usually means that the device is not present on the
network.
8.7 Frequently Asked Questions
8.7.1 What kind of data transfer rates can I expect between the PLC
and the module?
Data transfer rates between the PLC and the module depend on a number of
variables, among them the number of words being transferred per command, the
amount of other network traffic at the time data is being transferred, and overall
processor scan times.
8.7.2 Is a .MDC available for configuration of the Module?
Yes. The CDROM that ships with the module should have a version for both
Concept 2.5 and 2.6 in the ProTalk directory.
8.7.3 Does the module work in a remote rack?
he module is designed to be located in the chassis with the PLC and will not
operate in a remote chassis. If your application requires remote placement of the
communication device you should investigate the other members of the ProLinx
family such as the 4202-MNET-DFCM. (if you require DF1 connectivity for
instance although many others are available) This module for example would
allow you to communicate with DF1 devices and allow you to map the contents of
its memory using Modbus TCP/IP.
8.7.4 Can I use the module in a hot backup system?
Support for Hot Backup is not currently implemented in the module. We are
currently investigating the addition of this functionality but until this development
can be finalized, it may be possible to use one of the 4000 series of ProSoft
communication products. Please call our technical support technicians when
considering this application.