GetFile (Retrieve a File)
The GetFile instruction is used to get a file from another PakBus datalogger.
Syntax
GetFile ( ResultCode, ComPort, NeighborAddr, PakBusAddr, Security, TimeOut, "LocalFile", "RemoteFile" )
Example
The following example program shows the use of the GetFile instruction. The datalogger is connected to another datalogger via the COMC1 (C1/C2) serial port. The GetVariables instruction is used to get the name of the last file stored by the TableFile instruction in the remote datalogger. The datalogger then compares this last file name to see if it has changed since the last GetVariables attempt. If the file has changed the datalogger retrieves the new file.
The Files Manager setting in the datalogger can be used to manage these retrieved files.
Public LastFileName As String * 25, CompLastFileName As String * 25
Public ResultGetVar, ResultGetFile
BeginProg
SerialOpen (COMC1,57600,0,0,10000)
Scan (1,Sec,3,0)
GetVariables
(ResultGetVar,COMC1,0,3000,0000,0,"Public","LastFileName",LastFileName,1)
If LastFileName<>CompLastFileName
GetFile
(ResultGetFile,COMC1,0,3000,0000,0,LastFileName,LastFileName)
CompLastFileName=LastFileName
EndIf
NextScan
EndProg
Remarks
The GetFile instruction is used to retrieve a file stored on a remote datalogger. The name of the device or directory must also be included (for example, "USR:file"). PakBus datalogger device options are: CPU: = datalogger CPU drive; SSD: = datalogger SSD drive; CRD: = memory card; USB: = SC115 or external USB drive; CS9: = SC115; or USR: = user defined drive. The remote datalogger may be using TableFile, FileWrite, or some other means to store the file.
NOTE: In GRANITE Datalogger Modules, the USB device is an external USB drive and the CS9 device is an SC115. In all other dataloggers, the USB device is the SC115.
If PakBus encryption is enabled in the datalogger, by default the datalogger will encrypt the communications sent using this instruction. To disable encryption for one or more Pakbus addresses, use the EncryptExempt instruction. This is useful if a remote device does not support encryption (such as a CR200 or an AVW200).
Parameters
Result
The variable in which a response code for the transmission will be stored. A zero indicates a successful transaction. A positive value indicates that there was no response to the request from the remote. A negative value indicates some other type of error occurred. The codes that can be returned are:
| Code | Description |
|---|---|
| 0 | Successful. |
| -1 | Response received but permission denied. |
| -2 | Illegal drive, cannot open the file in the remote, or destination drive full. |
| -9 | Wrong fragment sent to the remote. |
| -14 | Too many files opened in the remote. |
| -16 | Table name and/or field name not present in the remote datalogger, or the field is read only in the destination datalogger. |
| -17 | Data type not supported. |
| -18 | Array in the sending datalogger is not dimensioned large enough to accommodate the values to be sent or array in the receiving datalogger is not large enough to accommodate values received |
| -20 | Out of Comms memory. |
| -21 | Failed to route packet when routing is set to auto-discover and route is not yet known. |
| -22 | Communication port buffer exceeded. |
| -25 | Cannot seek in the file. |
| -26 | Cannot open the local file. |
| -27 | DialSequence/EndDialSequence returned False so communication did not occur. |
| 1, 2..n | The number of timeouts waiting for a response. The value will increment with each successive failure. After a 0 or negative response, the value will start over at 1. |
ComPort (Communications Port)
The communications port that will be used by the instruction. Right-click to display a list. Options vary depending on the instruction.
| Alphanumeric | Description |
|---|---|
| ComRS232 | RS232 port of the datalogger |
| ComUSB | USB of the datalogger |
| ComME | Datalogger CS I/O port; modem enabled |
| Com310 | Datalogger CS I/O port; COM310 modem |
| Com320 | Datalogger CS I/O port; COM320 modem |
| ComSDC7 | Datalogger CS I/O port; SDC7 |
| ComSDC8 | Datalogger CS I/O port; SDC8 |
| ComSDC10 | Datalogger CS I/O port; SDC10 |
| ComSDC11 | Datalogger CS I/O port; SDC11 |
| ComC1 | Datalogger control terminals 1 & 2 |
| ComC3 | Datalogger control terminals 3 & 4 |
| ComU1 | Universal terminal pair U1 (TX) & U2 (RX) |
| ComU3 | Universal terminal pair U3 (TX) & U4 (RX) |
| ComU5 | Universal terminal pair U5 (TX) & U6 (RX) |
| ComU7 | Universal terminal pair U7 (TX) & U8 (RX) |
| ComU9 | Universal terminal pair U9 (TX) & U10 (RX) |
| ComU11 | Universal terminal pair U11 (TX) & U12 (RX) |
| ComRF | Integrated radio communication |
Type: Constant. For all instructions except SerialOpen, this parameter can also be a variable.
When communicating over TCP/IP, use the variable returned by the TCPOpen function for the ComPort. If PakBusTCPServer setting is being used rather than TCPOpen, use the Route(-PakBusAddr ) instruction for the ComPort parameter.
If a negative value is entered for the ComPort, the datalogger will not wait on a response from the destination device before proceeding to the next instruction.
NeighborAddr (PakBus Address to Neighbor Datalogger)
Used to specify a static route to the destination datalogger (for example, the PakBus PakBus® is a proprietary communication protocol developed by Campbell Scientific to facilitate communications between Campbell Scientific devices. Similar in concept to IP (Internet Protocol), PakBus is a packet-switched network protocol with routing capabilities. A registered trademark of Campbell Scientific, Inc. address of a "neighbor" datalogger that the host can go through to communicate with the destination datalogger).
If 0 is entered, the destination device is assumed to be a neighbor (i.e., the host datalogger can communicate with the destination directly). If a non-valid PakBus address is entered (a negative number or a number greater than 4094), the route to the destination device will be "autodiscovered" by other means in the PakBus network (such as beaconing or a Hello messages). If the instruction has a ResultCode parameter, an error code is returned until the route is discovered. When autodiscovery is used, the COMPort parameter is ignored.
Type: Integer between 1 and 4094
NOTE: By default, Campbell Scientific software uses the following PakBus addresses: LoggerNet 4094, VisualWeather 4094, PC400 4093, PC200W 4092, PConnect/PConnectCE 4091, RTDAQ 4090, Device Configuration Utility 4089.
Note that if the datalogger is configured as a leaf node The degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard. (as opposed as a router A device configured as a router is able to forward PakBus packets from one port to another. To perform its routing duties, a datalogger configured as a router maintains its own list of neighbors and sends this list to other routers in the PakBus network. It also obtains and receives neighbor lists from other routers. Routers maintain a routing table, which is a list of known nodes and routes. A router will only accept and forward packets that are destined for known devices. Routers pass their lists of known neighbors to other routers to build the network routing system.), setting the NeighborAddr to autodiscover should be used with care. A leaf node is aware only of its direct neighbors but has no knowledge of the rest of the PakBus network; therefore, it is not capable of "autodiscovering" a route to a destination datalogger that is not a direct neighbor. If the direct neighbors it can communicate with are not routers themselves, any communication packets sent will fail. Communication packets from the leaf node to the rest of the network also will fail if its direct router is no longer in the network.
When a leaf node is set to autodiscover it will attempt to communicate any time it is aware of a neighbor that is a router. This will result in an incrementing result code if that neighbor router is not aware of the destination address. If the leaf node's neighbor is not a router or if the leaf node has no neighbors, communication will not be attempted and a -21 is returned.
PakBusAddr (PakBus Address)
The Pakbus PakBus® is a proprietary communication protocol developed by Campbell Scientific to facilitate communications between Campbell Scientific devices. Similar in concept to IP (Internet Protocol), PakBus is a packet-switched network protocol with routing capabilities. A registered trademark of Campbell Scientific, Inc. address of the device that will be contacted as a result of this instruction. Each PakBus device in the network must have a unique
address.
If PakBus encryption is enabled in the datalogger, by default the datalogger will encrypt the communications sent using PakBus communication. To disable encryption for one or more Pakbus addresses, use the EncryptExempt instruction. This is useful if a remote device does not support encryption (such as a CR200 or an AVW200).
Type: Integer between 1 and 4094
NOTE: By default, Campbell Scientific software uses the following PakBus addresses: LoggerNet 4094, VisualWeather 4094, PC400 4093, PC200W 4092, PConnect/PConnectCE 4091, RTDAQ 4090, Device Configuration Utility 4089
Security
The security code of the remote datalogger. 0 is entered for this parameter if no security is set in the destination datalogger.
Type: Integer
If security is enabled, it must be unlocked to level 3.
NOTE: If other data logger security settings, such as TCP password and PakBus Encryption are set, these must also match between remote and local data loggers for successful data logger to data logger communications to occur.
TimeOut (Wait Time)
The amount of time, in 0.01 seconds, that the datalogger should wait for a response before considering the instruction to have failed. The datalogger waits for the TimeOut period to expire before proceeding to the next instruction.
If 0 is entered for this parameter, then the datalogger will use a time based on its known route to the destination device.
Type: Constant
NOTE: In RF400 communication, the timeout should be sufficiently long to avoid collisions (the default of 0 should accomplish this, or use at least 500 ms).
LocalFile (Local File)
The Device and Filename, enclosed in quotes, where the retrieved file should be stored ("Device:FileName").
Type: String variable
RemoteFile (Remote File)
The Device and Filename, enclosed in quotes, of the file that is retrieved from the remote datalogger ("Device:Filename"). PakBus datalogger device options are: CPU: = datalogger CPU drive; CRD: = memory card; USB: = SC115 or external USB drive; CS9: = SC115; or USR: = user defined drive.
NOTE: In GRANITE Datalogger Modules, the USB device is an external USB drive and the CS9 device is an SC115. In all other dataloggers, the USB device is the SC115.
Type: String variable
You will likely need some way to manage the files that are retrieved from the remote datalogger. Otherwise, these files may fill up the drive on which they are being stored and subsequent files will not be saved. You can do this programmatically using the FileManage instruction, or you can set up a type of ring memory using the Files Manager setting in the datalogger's status table. The Files Manager setting lets you define the maximum number of files that are kept from a specific PakBus device, with the oldest file being deleted prior to writing the new file once that maximum is reached.