Specifications

1 Introduction
1.1 Purpose
The MCS-DR, or “monitoring and control system - data recorder” is a data capture and storage sys-
tem for the LWA radio telescope project implemented using general-purpose, commercially available
off-the-shelf (COTS) components. A preliminary design for the MCS-DR has been completed and
validated. Specifically, we have demonstrated the ability to reliably record up to 10 hours of data
at 115 MiB/s. This document will summarize progress made in design and testing of the MCS-DR
and will describe the hardware and software components that make up the MCS-DR.
1.2 Background
MCS-DR is part of MCS “monitoring and control system”. The MCS, in turn, is part of the LWA
“Long Wavelength Array”. The MCS-DR records the data generated by the LWA’s Digital Pro-
cessing (DP) subsystem, and each individual computer is connected by 10-Gigabit Ethernet (10
GbE) to one of five possible inputs from the DP [1]. MCS controls storage and retrieval of data to
and from MCS-DR. The design of each computer in the MCS-DR subsystem is identical except for
configuration files.
1.3 Document Conventions
Numbers, units, and their associated prefixes and suffixes conform to the standard of IEC 60027-2
[2]. Specifically, the prefixes Ki, Mi, Gi, and Ti refer to 2
10
, 2
20
, 2
30
, and 2
40
, respectively. Likewise,
the prefixes K, M, G, and T refer to 10
3
, 10
6
, 10
9
, and 10
12
, respectively. If a unit specifies a binary
size or rate, an uppercase B represents a byte, whereas a lowercase b indicates an individual bit (i.e.
MB = Megabyte, or 1,000,000 bytes, and Kb = kibibit or 1,024 bits).
1.4 Summary of Current Status of MCS-DR Development
The MCS-DR PC hardware selection’s suitability has been verified in each of three critical aspects.
The three critical aspects are writing to disk, moving data through memory and kernel function
calls, and moving data from the physical network into system memory – all at the target data rate
2