Chapter 6. Connector pin-outs

6.1 Output port and breakout box RECORDER connector

This is a standard 26-pin military specification bayonet plug, conforming to MIL‑DTL‑26482 (formerly MIL‑C‑26482). A typical part-number is 02E-16-26P although the initial “02E” varies with manufacturer.

Suitable mating connectors have part-numbers like ***-16-26S and are available from Amphenol, ITT Cannon and other manufacturers.

Pin assignments used when the High Gain option is not fitted:

Pin	Function	Pin	Function
A	Velocity +ve, vertical ch.	P	Calibration signal (all channels)
B	Velocity –ve, vertical ch.	R	Calibration enable (all channels)
C	Velocity +ve, N/S ch.	S	Not connected
D	Velocity –ve, N/S ch.	T	Not connected
E	Velocity +ve, E/W ch.	U	One-second mode *
F	Velocity –ve, E/W ch.	V	N/S centring motor *
G	Mass position, vertical ch.	W	E/W centring motor *
H	Not connected	X	Vertical centring motor *
J	Mass position, N/S ch.	Y	Digital ground / Motor return *
K	Not connected	Z	Not connected
L	Mass position, E/W ch.	a	Not connected
M	-12V DC (3-way power opt)	b	Power ground
N	Signal ground	c	+12V DC supply

* see notes on following page

Wiring details for the compatible socket, ***-16-26S, as seen from the cable end.

Note: In the standard instrument, pin U selects one-second mode when grounded to pin Y, which is digital ground.

In instruments with the remote nulling option fitted, pins V, W and X provide access to the motors diving the nulling potentiometers. Pin Y serves as the return for the motor currents.

In instruments with the digital nulling option fitted, grounding pin U for seven seconds initiates the automatic centring process.

These connectors are plug-compatible with the Güralp 3ESP, so you can use Güralp 3ESP hand-held control units and breakout boxes to monitor the low-gain velocity outputs and run calibrations. Pressing ENABLE and CENTRE on a Güralp 3ESP hand-held control unit activates pin U and switches the 40T into one-second mode for as long as the buttons are held down. You must do this before you can monitor mass position outputs, e.g. for offset nulling.

Note: 40T units with the optional additional high-gain outputs cannot be used with a Güralp 3ESP breakout box. The pin-outs for these sensors are given in the next section.

Pin R, Calibration enable, is equivalent to the vertical calibration enable line on a Güralp 3ESP, so you can calibrate all channels by setting up Scream! or a hand-held control unit to calibrate the vertical channel.

6.2 Output port and breakout box RECORDER connector (high-gain option)

These units use the same plug with the following pin assignments. High gain velocity outputs are denoted HGV.

Suitable mating connectors have part-numbers like ***-16-26S and are available from Amphenol, ITT Cannon and other manufacturers.

Pin	Function	Pin	Function
A	Velocity +ve, vertical ch.	P	Calibration signal (all ch)
B	Velocity –ve, vertical ch.	R	Calibration enable (all ch)
C	Velocity +ve, N/S ch.	S	HGV -ve, vertical channel
D	Velocity –ve, N/S ch.	T	HGV +ve, vertical channel
E	Velocity +ve, E/W ch.	U	Acc/Vel (or Centre - see P17)
F	Velocity –ve, E/W ch.	V	N/S centring motor*
G	Mass position, vertical ch.	W	E/W centring motor*
H	HGV –ve, E/W channel	X	Vertical centring motor*
J	Mass position, N/S ch.	Y	Motor return*
K	HGV +ve, E/W channel	Z	HGV -ve, N/S channel
L	Mass position, E/W ch.	a	HGV +ve, N/S channel
M	-12V DC (3-way power opt)	b	Power ground
N	Signal ground	c	+12V DC supply

* see notes in section 6.1.

Wiring details for the compatible socket, ***-16-26S, as seen from the cable end.

6.3 Breakout box power connector

This is a standard 10-pin military-specification bayonet plug, conforming to MIL‑DTL‑26482 (formerly MIL‑C‑26482). A typical part-number is 02E-12-10P although the initial “02E” varies with manufacturer.

Suitable mating connectors have part-numbers like ***-12-10S and are available from Amphenol, ITT Cannon and other manufacturers.

Pin	Function
A	Power 0 V
B	+12 V DC supply
C	Not connected
D	Not connected
E	Not connected
F	Not connected
G	Not connected
H	–12 V DC supply (3-way power option)
J	Not connected
K	Not connected

Wiring details for the compatible socket, ***-12-10S, as seen from the cable end.