The central site acquisition computer is running the OS2/Warp operating system and the Nanometrics NAQS software. It receives data continuously from the remote stations over leased telephone lines using modems. The Nanometrics CP8 Communications Processor receives the data from the modems at about a 1 second rate and time stamps the data accurately using the GPS satellite reciever clock. The data is then written to hard disk where it can hold about a month of data before it is overwritten. Data of interest can be extracted from the hard disk and transferred to another computer for processing using a T1 network connection. Also, a continuous stream of the data is extracted from the hard disk at 5 minute intervals and transferred over the network to two other systems for backup and printing. The Nec printer is used to display one component of one station. A duplicate system is ready in case this system fails.
This system is running the Linux operating system. It receives a copy of all the data from the acquisition computer and saves it on disk. There is enough space to hold about 3 months of data before it is overwritten.
The modem is used to phone the remote dial-up stations and download state of health files and data of interest. This data is then combined with the data from the acquisition system and archived to Exabyte tape or read/writeable CDROM on another system.
The SCSI card is used to interface to the removable hard disks used by the remote dial-up stations. A spare disk can be initialized and brought out to one of the remote dial-up stations. The old disk can then be brought back and any pertinent data extracted. This allows for extended periods of time when the phone line is down.
This system is running the Linux operating system and receives a copy of all the data from the acquisition system and then plots all 21 seismic channels on the Epson printer.
These sites send data continuously to the central site acquisition computer over leased telephone lines.
The Orion disk can hold about a month of data before the data is overwritten. The central site backup computer phones these sites for data.