Minicom Advanced Systems CMG-DCM manual Cmg-Dcm

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CMG-DCM

The stand-alone DCM has three RS232 serial ports brought out on 10-pin mil- spec connectors, labelled PORT A, PORT B and DATA OUT. The labelling is provided for convenience, and can be ignored if it does not match your site requirements: each port may be used for communication in either or both directions.

Each serial port has its own configuration screen, with a number of options beginning serial.x (where x is the internal number of the serial port). The configuration options for all the ports are as follows:

serial.x.baudrate : This option alters the speed of communication across each serial link, in bits per second.

For ports connected to digitizers, you should ensure that the baud rate is high enough to allow all the data to be transmitted at the rates you have chosen. As an example, for three streams transmitting at 100 Hz, a rate of 9600 baud is usually sufficient. Modern modems can normally operate at rates up to 57600 baud (~56 kbits/s), although the telephone or transmission lines may not support such a high rate. The same is true of radio telemetry links.

The DCM's serial ports operate using frames of 8 data bits, no parity bits, and one stop bit.

serial.x.device : The pathname of the Linux device corresponding to this serial port. You should not need to change this option.

serial.x.handshaking : The flow-control (handshaking) protocol used across each serial link. There are three options:

•

•

off : Transmit data across the serial link without handshaking, i.e. assume that the link is always ready to send or receive data.

rts/cts : Use the Ready To Send/Clear To Send handshaking method, where two separate lines within the serial cable are used to control the flow of data. This is the most reliable method since accomplished in hardware, but is not feasible for long-distance or complex connections.

•xon/xoff : Send the two special characters ^Q (17) and ^S (19) as part of the data stream to request that data transfer be started and stopped. This method requires only a single connection, but assumes that the special characters will be received correctly every time.

serial.x.name : The name of this serial port. You should not ordinarily change this setting.

serial.x.ppp : You can use any of the serial ports to establish a network connection with a computer using the PPP protocol by setting the serial.x.service option, below, to ppp. The DCM uses the standard Linux

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Contents CMG-DCM Table of Contents December Inside the DCM Introduction CMG-DCM Inside the DCM Serial port services Network servicesSee .4, Connecting to a local network for full details Overview Installing the CMG-DCMPower supply Connecting to a single computer Connecting over a serial linkConnecting over Ethernet 192.168.0.xUsing an internal modem Connecting over USBConnecting to a local network Gcfgdbset option-namenew-value Wi-Fi Connecting to the InternetConnecting digitizers and external hardware Setting up the CMG-DCMWeb setup Setting up digitizers Using Scream DCM as a data store UsageGeneral notes Gnblocks port-number Page CMG-DCM DCM as a GCF data source Accessing the DCM command line through gcfout Sensor arrays DCM as a network data hub Communicating with digitizers Configuring digitizers Data storage and retrieval Using miniSEED format Real-time data transmission CD1.0 and CD1.1 Troubleshooting DCM installations Cannot Gcfping the DCMs Scream! server Cannot see the DCMs Web site over Http or HttpsCannot connect to the DCMs Scream! server Can Gcfping the DCMs Scream! server, but no data appears DCM is not receiving any data streamsUse the Serial port configuration → port name Web page, or DCM is receiving streams, but they do not contain any data143032 up 34 min, load average 1.24, 1.32 Configuration options GeneralDisk CMG-DCM Serial port configuration CMG-DCM Page Network configuration Ethernet portStatic routes DNS setup Incoming mail setup Outgoing mail setup Remote access Administrators PPP Mgetty Data transfer ScreamScream! Client AutoDRMCD1.0 Http serverHttp client CD1.1 CD1.1 subframe configuration DSS Server configuration Seed Page CMG-DCM Actions Data ViewerIcon bar Stream listDigitizer Setup General digitizer settings Digitizer output control CMG-DCM Trigger criteria CMG-DCM Tap # Rate Bandwidth Samples/s Auxiliary Mux channels Sensor mass control Disk tools Partition, and format diskCheck disk filesystem Flush flashRecent Log Entries Disk filesCamera Network configuration SummaryDNS configuration Data Out Port, Serial Port A, Serial Port BDisk Status Flash StatusTamper lines Software Versions Inside the DCM File systems CMG-DCM Command line tools Configuration Digitizer console access Monitoring Data flowDigitizer status Tamper lines Updating the DCM Over the InternetFrom the hard disk Removing support packagesFirmware Libgconfigdb Appendix a Connector pinouts Appendix A.1 Modular DCM unitsPort a and B Data OUT portUSB connector Network connectorAppendix A.2 Integrated DCM units DM/AM module outputAppendix B Sensor and digitizer types Appendix B.1 Sensor response codesAppendix B.2 Digitizer type codes Digitizer
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