Protocol Operation

Because the wireless reader can become unavailable at times, the Industrial Ethernet protocols are actually run from the base station. The base station is directly wired to the Ethernet network and is online continuously (even when the reader is unavailable). In this way the Ethernet protocol operation is not disrupted when the reader is unavailable. This results in a few special considerations.

Ethernet Address

Because the Ethernet protocols are run from the base station, you must use the base station Ethernet address when configuring the protocol. For example, when configuring EtherNet/IP using the RSLogix5000 software package, you select the DM8000 reader but you must enter the IP address of the base station (not the reader). The PLC using the protocol must communicate with the base station.

PLC Triggering

Because the wireless reader can become unavailable at times, triggering from the PLC is not supported on wireless readers. The PLC will receive all read results triggered from the reader. Also, SoftEvents and DMCC commands are supported (when the reader is available).

SoftEvents

SoftEvents triggered from the PLC are supported. However, these events will fail if the reader is unavailable. Such a failure will be signaled by the ‘General Fault’ bit.

Note: Some operations assigned to SoftEvents are in general not supported on any handheld DataMan readers (for example, ‘Train Code’, ‘Train Focus’, ‘Train Brightness’). Unsupported operations will also result in the ‘General Fault’ signal being set.

DMCC

DMCC commands issued from the PLC are supported. However, these events will fail if the reader is unavailable. Depending on which Industrial Ethernet protocol is in use, the failure will be signaled either with the ‘General Fault’ signal or an error status return code. The new DMCC error return code ‘105’ has been established to signal that the reader is unavailable.

Note: When issuing DMCC commands from the PLC to a wireless reader, do not change the DMCC response format (that is, do not issue the command ‘COM.DMCC-RESPONSE’). Doing this may disable DMCC operation on the wireless reader. This command can be used on non-Industrial Ethernet connections such as Telnet.

Offline Buffering

When the wireless reader is physically out of range of the base station, it will automatically buffer all reads. Buffer capacity varies according to a number of factors. However, typically several hundred reads can be stored. These buffered reads are also preserved if the reader enters hibernation (sleep mode). When the reader is brought back into range of the base station the buffered reads will automatically be downloaded.

If this offline buffering situation is anticipated in the user application, then Industrial Ethernet protocol buffering should also be enabled. Protocol buffering will allow a PLC to control the rate that read results are returned to the PLC. This prevents the PLC from becoming overwhelmed by a rapid flow of read results. Refer to the specific Industrial Protocol section of this document for details of enabling and utilizing protocol buffering.

Note: The base station can buffer up to 500 results.

Status of Industrial Protocols

The Status field of the industrial protocols (in Setup Tool, under Industrial Protocols tab) displays the last logged message of the status dialog. The message will remain displayed until another message is logged. If no industrial protocol is enabled, the status field remains blank.

Status messages vary by protocol, and some protocols do not log any messages. See the table below for a summary of messages for protocols that display them:

Protocol/Reader	Message	Description
Wi-Fi readers	Industrial ethernet protocols shutdown	Displayed if no protocol is running
	Proxy %s connection opening	Opening connection to Wi-Fi reader, s == connection type ("Command", "Result", or "User DMCC")
	Proxy %s open	Connection open, s == connection type ("Command", "Result", or "User DMCC")
	Proxy %s not open	failed to open connection, s == connection type ("Command", "Result", or "User DMCC")
	Proxy %s closed	connection has been closed, s == connection type ("Command", "Result", or "User DMCC")
Modbus TCP	Modbus TCP starting...	Protocol starting
	Modbus TCP: Server Setup Failed	Failed to start server
	Modbus TCP running	Protocol running
	Modbus TCP: Add block %s failed	Data block configuration error
	Modbus TCP control block %s	Status of ModbusTCP data block, s == “info” or “error”
SLMP Protocol	Opening SLMP scanner connection %s:%x	starting SLMP connection, s==IP address, x==port number
	SLMP scanner connection established %s:%x	SLMP connection established, s==IP address, x==port number
	SLMP scanner connection %s:%x rejected	PLC has rejected the connection, s==IP address, x==port number
	SLMP scanner connection %s:%x faulted	Miscellaneous connection fault has occurred, s==IP address, x==port number
	SLMP scanner poll rate set too low	Configured SLMP poll rate is set too low
	SLMP scanner connection normal %s:%x	SLMP connection has been restored, s==IP address, x==port number
	SLMP Scanner control block %s	Status of SLMP data block, s == “info” or “error”
	SLMP Scanner failed transfering '%s' block	Comm error, failed to transfer a data block, s==block name