DT80 Range Host Communications
From dataTaker Wiki (FAQ)
USB 2.0 Compliant?
The DT80 range logger USB slave port operates as a "full speed" (12Mbps) USB 2.0 compliant device. It does not support "high speed" (480Mbps) operation.
Does the logger appear as a ‘plug & play’ device via USB?
Yes, when the logger is connected the DTUSB driver will be installed.You may be prompted to insert the driver CD. The driver is supplied with the dataTaker Resource CD or will be automatically located on the web by WinXP.
Can a USB hub be used?
Yes.
Can I connect over the web?
Yes, you can connect to the DT80 range loggers over a web connection in several ways.
- Full host access and control via a conventional host package e.g. DeTransfer or dEX command window
- FTP using a FTP client or Web browser allows access to data store files. Files can be moved to your PC then data viewed using DeView or DeLogger4.
- The logger can also send files to a remote FTP server, see this example for details. This is where the DT80 controls the transfer of data files to a remote FTP storage location such as a website or personal storage site that may be provided by your ISP.
- Web Interface, Enhanced web interface called dEX (available Series 2 & 3 only) provides data retrieval to CSV, data viewing through tables or graphical mimics plus control and programing via a web browser. Series 1 loggers provide (from Version 6 firmware onwards) a simpler web browser interface (Classic Interface) with data retrieval, current data and status views from included HTML web pages or user developed custom pages.
- Modbus SCADA interface for access to current data and status.
NOTE: You can see FTP folders from IE and other browsers. Must be remote request from FTP Client. Supports anonymous login – read only.
NOTE: To connect a non modem DT80 range data logger to the internet you will generally use a router or modem with router capability. The router must be configured appropriately to make the DT80 visible to the internet. This may include setup of port forwarding for the HTTP, FTP and COMMAND ports used. Some general information about port forwarding can be found here. More information about setting up router functions generally can be found here.
What if I connect to USB and Serial ports simultaneously?
The USB and serial ports may be physically connected at the same time but the logger will talk to only one external host at a time on a first come first served basis.
NOTE: USB comms is default on reset if both are connected. Communications will autoswitch to whichever port was used last.
Can the logger connect to my Ethernet network?
Yes, using the standard Ethernet port you can connect to a LAN or WAN.
Can multiple users connect over Ethernet?
Yes, multi user has limited functionality. The same actual data is returned to all connections. Built-in and Custom HTML web pages can be used to display current data and status relevant to a particular user type.
Is the RS232 port Isolated?
The RS232 Host port is not isolated, but the Communications/Digital/Power section is isolated from the Analog system.
What sort of RS232 cable do I need?
For connection to a PC, a null modem cable is required, available from dataTaker as P/N PROIBM-6. For connection to a modem, a straight through cable is required, available from dataTaker as P/N PROMOD-6.
| DT80 Pin No. | PC Pin No. |
| 2 (RXD) | 3 (TXD) |
| 3 (TXD) | 2 (RXD) |
| 5 (Sig Gnd) | 5 (Sig Gnd) |
| 7 (RTS) | 8 (CTS) |
| 8 (CTS) | 7 (RTS) |
| DT80 Pin No. | Modem Pin No. |
| 1 (DCD) | 1 (DCD) |
| 2 (RXD) | 2 (RXD) |
| 3 (TXD) | 3 (TXD) |
| 4 (DTR) | 4 (DTR) |
| 5 (Sig Gnd) | 5 (Sig Gnd) |
| 6 (DSR) | 6 (DSR) |
| 7 (RTS) | 7 (RTS) |
| 8 (CTS) | 8 (CTS) |
| 9 (RI) | 9 (RI) |
USB Isolation?
As per RS232 Isolation above.
Do I need to upgrade DeTransfer?
No, but some DeTransfer menu functions are not applicable to the DT80 range loggers at present.
NOTE: Menu items;Prepare card for upgrade
Do I need to upgrade the LabVIEW™ driver?
No, but some supplied VIs may require minor modification to suit user requirements.
Can I print direct from the logger?
Yes, but only to a serial RS232 printer that will accept standard ASCII text and control characters. These units are commonly known as Line Printers. Other suitable printers may include the small docket printers used for POS (Point Of Sale) transactions. USB printers are not supported.
Where can I get the latest USB driver for the DT80 range from the web?
Yes. DTUSB can be down loaded from the dataTaker web site dataTaker down load page
Can I change the allocated COM port number when using a USB-to-serial adapter?
Yes.
- Run Windows Device Manager
- Locate the required COM port under "Ports (COM and LPT)" and double click it to display Properties window
- Select Port Settings tab
- Press Advanced...
- Select a different unused COM port number.
Why can't I establish a PPP connection with a modem?
Earlier versions of DT80 firmware did not switch to PPP mode until Windows sent the word CLIENT. Windows sends this automatically when establishing a direct serial PPP connection, but not for modem connections.
DT80 range firmware version 7.08 and later support proper PPP handling for both direct and modem connections. Upgrade your firmware to the latest version.
If it is not possible to upgrade the firmware, you will need to create and save a login script (.scp file) such as the following:
proc main delay 5 transmit "^M^J" delay 5 transmit "CLIENT" waitfor "CLIENTSERVER" endproc
and then enable it in the Network Connection / Properties / Security tab ("Run Script" checkbox).
When I establish a PPP connection to the DT80 range logger, I lose internet access on my host computer
This can occur if the host PC has two TCP/IP connections: a serial PPP connection to talk to the logger, and an Ethernet connection to connect to a local area network and the Internet. The problem occurs if Windows sets the PPP connection as the "default route", rather than the Ethernet connection. In this case all internet traffic from the host will be forwarded to the logger rather than the LAN.
The following may help resolve this issue:
Open Network Settings on the Windows Control Panel. This should list your PPP and LAN connections. Right click on the PPP connection and select "Properties", then the "Networking" tab, then select "Internet Protocol (TCP/IP)", then click the "Properties" button, then click the "Advanced" button. On the "General" tab you should now see a checkbox marked "Use default gateway on remote network". REMOVE the tick from this checkbox.
After making this change it may be necessary to reboot the host PC in order for it to fully take effect.
Can I reduce the time it takes to establish a PPP connection?
When connecting to the logger via PPP, it can take up to 30 seconds to connect, during which time Windows displays "Registering your computer on the network" or similar. This is due to Windows attempting to negotiate various PPP protocol options, which the DT80 range loggers do not support. To speed up this process, try the following:
Open Network Settings on the Windows Control Panel. This should list your PPP and LAN connections. Right click on the PPP connection and select "Properties", then the "Networking" tab, then click the "Settings" button which should bring up a "PPP Settings" dialog box. This should contain an "Enable software compression" checkbox. REMOVE the tick from this checkbox.
Why doesn't the modem connected to the logger auto answer?
Early versions of the DT80 and DT81 did not allow the modem to answer calls if the logger was in its sleep mode. The loggers that have this behavior are as follows.
- DT80: Serial numbers less than 083355 (sold before 29-Mar-2007)
- DT81: Serial numbers less than 083798 (sold before 13-Sep-2007)
- DT85: None affected.
The reason that these loggers will not allow the modem to auto answer is that when they are in sleep mode the DTR (Data Terminal Ready) signal is held inactive, which indicates to the modem to hang-up a call, or in this case not allow a new call to be answered. If the logger is awake when the call arrives then there is no problem as DTR is active and the modem can answer the call.
There are two possible workarounds:
- Set P15=2 to ensure that the logger never goes to sleep.
- Connect RI on the Host Port connector to CTS on the serial sensor port. This will cause the logger to wake up when the ring starts. You must also ensure that the logger does not go back into sleep mode before the call is established (ie while the modems are "training up", establishing common protocols for transmission) otherwise the call will be terminated prematurely. To do this you must ensure that P17 is set to a time period greater than the time it takes to establish a connection. For a PSTN modem this might be, say, 60 seconds.
None of this is necessary with newer model loggers as the RI signal will cause the logger to wake and DTR is held active when the logger is in its sleep mode.
