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Stream IDs explained

GCF data from digitisers are identified by the combination of System ID and Stream ID. The “System ID” identifies the digitiser from which the data originate and each stream from a given digitiser is then identified by its “Stream ID”. Each Stream ID is composed of two parts, the “Serial Number” and a two-character suffix to identify which data are contained in the stream. These terms are explained in the following sections.

System ID

The System ID is factory-set to contain the sales order or works order number. It can be re-programmed to contain any combination of upper-case letters (A-Z) and digits (0-9), usually up to a maximum of five characters in length. It cannot begin with the character 0. The ranges of permissible IDs is determined by the digitiser type as shown in the table below:

Digitiser typeRange of permissible IDs
DM24 MkⅡ All 1-, 2-, 3-, 4- and 5-character IDs plus 100000 to ZIK0ZJ
DM24 MkⅢ and CD24 All 1-, 2-, 3-, 4- and 5-character IDs plus 100000 to 13YDJ3
Affinity and Minimus All 1-, 2-, 3-, 4-character IDs plus 10000 to 18Y67

You can re-programme the System ID by:

The System ID is typically set to a code identifying the project or network in which the digitiser is deployed.

Serial Number

The Serial Number is factory-set to contain the serial number of the digitiser or, in the case of digital instruments, the serial number of the instrument. It can be re-programmed to contain almost any combination of upper-case letters (A-Z) and digits (0-9), up to a maximum of four characters in length.

Due to the encoding method used, Serial numbers must be alphabetically less than ZIK0 – see the GCF quick reference for details.

You can re-program the Serial Number by:

The Serial Number is typically set to a code identifying the location or node of the network in which the digitiser is deployed.

Data source suffix

The Stream ID ends in a two-character suffix which identifies the data source. The possible values are given in the table below.

Suffix Data source
Main outputs (See note 1, below)
Z0 SENSOR A, Vertical channel, main output, first (fastest) tap
Z2 SENSOR A, Vertical channel, main output, second tap
Z4 SENSOR A, Vertical channel, main output, third tap
Z6 SENSOR A, Vertical channel, main output, fourth (slowest) tap
N0, N2, N4, N6 SENSOR A, North/South channel, main output, first to fourth tap, respectively
E0, E2, E4, E6 SENSOR A, East/West channel, main output, first to fourth tap, respectively
Mass positions
M8 SENSOR A, Vertical channel, mass position output
M9 SENSOR A, North/South channel, mass position output
MA SENSOR A, East/West channel, mass position output
Meta-data and text streams
00 The status stream
IB The contents of the information blocks (only sent at boot-up or on request – see “Using InfoBlocks with Scream” for details).
BP Byte-pipe data (from text-to-GCF converters)
01 Unified status (structured state-of-health information). Essential when a DM24 or CD24 digitiser is connected to a Platinum systemA "platinum system" is any system running the Platinum operating system. This includes stand-alone acquisition systems such as EAMs and NAMs, DAS units such as the Affinity and DM24SxEAM and digital instruments with built-in acquisition systems such as the 3TDE, 40TDE or 5TDE., such as an EAM or NAM, but otherwise of little use. This stream can be enabled from the digitiser command line with +monitor and disabled with -monitor
CD Structured status for CD1.1 (obsolete)
Second instrument (See note 2, below)
Z1, Z3, Z5, Z7 SENSOR B, Vertical channel, main output, first to fourth tap, respectively
N1, N3, N5, N7 SENSOR B, North/South channel, main output, first to fourth tap, respectively
E1, E3, E5, E7 SENSOR B, East/West channel, main output, first to fourth tap, respectively
Auxiliary inputs and calibration returns
X0 SENSOR A, Auxiliary input, first (fastest) tap
X2 SENSOR A, Auxiliary input, main output, second tap
X4 SENSOR A, Auxiliary input, main output, third tap
X6 SENSOR A, Auxiliary input, main output, fourth (slowest) tap
X1, X3, X5, X7 SENSOR B, Auxiliary input, first to fourth tap, respectively
C0 SENSOR A, Calibration signal return, first (fastest) tap
C2 SENSOR A, Calibration signal return, main output, second tap
C4 SENSOR A, Calibration signal return, main output, third tap
C6 SENSOR A, Calibration signal return, main output, fourth (slowest) tap
MB SENSOR A, multiplexed input B (used as calibration signal return on early digitisers)
MC SENSOR A, multiplexed input C
MD SENSOR A, multiplexed input D
ME SENSOR A, multiplexed input E (connected to an internal thermometer on some models)
MF SENSOR A, multiplexed input F
Triggered data
ZG SENSOR A, Vertical channel, triggered output, first (fastest) tap
ZI SENSOR A, Vertical channel, triggered output, second tap
ZK SENSOR A, Vertical channel, triggered output, third tap
ZM SENSOR A, Vertical channel, triggered output, fourth (slowest) tap
NG, NI, NK, NM SENSOR A, North/South channel, triggered output, first to fourth tap, respectively
EG, EI, EK, EM SENSOR A, East/West channel, triggered output, first to fourth tap, respectively
ZH, ZJ, ZL, ZN SENSOR B, Vertical channel, triggered output, first to fourth tap, respectively
NH, NJ, NL, NN SENSOR B, North/South channel, triggered output, first to fourth tap, respectively
EH, EJ, EL, EN SENSOR B, East/West channel, triggered output, first to fourth tap, respectively
XH, XJ, XL, XN Auxiliary channel, triggered output, first to fourth tap, respectively
Strong motion and Causal-filtered (low-latency) data (See note 3, below)
ZO, NO, EO Windowed minimum for Vertical, North/South and East/West, respectively
2O Windowed minimum for two-dimensional, horizontal resultant
3O Windowed minimum for three-dimensional resultant
ZP, NP, EP, 2P, 3P Windowed PGA for Vertical, North/South, East/West, horizontal resultant and three-dimensional resultant, respectively
ZQ, NQ, EQ, 2Q, 3Q Windowed maximum for Vertical, North/South, East/West, horizontal resultant and three-dimensional resultant, respectively
ZR, NR, ER, 2R, 3R Windowed RMS for Vertical, North/South, East/West, horizontal resultant and three-dimensional resultant, respectively
ZS, NS, ES, 2S, 3S Windowed spectral intensity for Vertical, North/South, East/West, horizontal resultant and three-dimensional resultant, respectively
ZT, NT, ET, 2T, 3T Windowed average for Vertical, North/South, East/West, horizontal resultant and three-dimensional resultant, respectively
ZC, NC, EC On an S6 digitiser, SENSOR A, Causal-filtered (low-latency) data for Vertical, North/South and East/West, respectively
ZD, ND, ED On an S6 digitiser, SENSOR B, Causal-filtered (low-latency) data for Vertical, North/South and East/West, respectively (See note 2, below)
ZE, NE, EE On an S3 digitiser, Causal-filtered (low-latency) data for Vertical, North/South and East/West, respectively

Notes

  1. The letters Z, N and E (which identify the three main inputs and are used throughout this table) can be replaced by any three consecutive letters of your choice: see section 9.2 of the Scream manual for details.

  2. Digitisers with a SENSOR B input can either use the stream suffices in this section (the default) or be programmed with a second serial number for the second instrument, in which case they will use the same suffices as the SENSOR A instrument. You can programme a second serial number

  3. Strong motion data and low-latency, causal-filtered streams are described in section 8.1.1.4 of the EAM manual.

GCF Examples

Here are some examples of typical stream IDs with their constituent parts decoded:

SEED Output

SEED data from EAMs, NAMs and Scream are named using SCNL (Station, Channel, Network, Location) notation. When automatic stream-name mapping (GCF to SCNL) is used:

The Channel name for both the status stream and the InfoBlock stream is SOH. The Location name for the status stream is 00 and, for the InfoBlock stream, 0B.

Note that the Platinum firmware on EAMs and NAMs allows you to completely or partially over-ride the automatic name mapping, so you can use any SCNL names that you wish. The examples below use automatically mapped names.

SEED Examples