I/O Connector (M9485A)

M9376A and M9377A have the I/O connectors which is used to synchronize the triggering of the analyzer with other equipment. M9376A and M9377A also has the port to generate the pulse for pulse measurement.

IO Port Assignments

The ports on M9376A/M9377A which are assigned to the ports 1 to 4 can be used as the Handler I/O as shown below at the default.  

Module

Port name

Signal name

Input/Output

Description

Port 1

 

I/O1

/READY FOR TRIGGER

Output

Indicates that the instrument is ready for triggering. This signal is changed to the Low level when the instrument is ready for receiving a trigger signal.

With the point trigger function on, it goes to the Low level when the instrument is ready to accept the trigger signal for the first point and goes to the High level when the trigger signal for the first point is received. When measurement of all measurement points is completed and the instrument is ready to receive the trigger signal for the first point of the next sweep, this signal goes to the Low level again.

Trig

/EXTERNAL TRIGGER

Input

An external trigger signal. When the trigger source is set to the "External," this port generates a trigger in respond to the trailing edge of a negative pulse.

I/O2

/INDEX

Output

Indicates that analog measurement is complete. The /INDEX signal changes to the Low level when analog measurement (all sweeps of all channels) is complete. When the handler receives the signal, it assumes that it is ready to connect the next DUT. However, no measurement data are available until data calculation is completed.

When the point trigger function is on, it goes to the High level before staring measurement of the first measurement point and returns to the Low level after completing measurement of all measurement points.

Port 2

 

I/O1

/SWEEP END

Output

A sweep completion signal. When measurement (all sweeps of all channels) and data calculation are completed, this signal provides a negative pulse.

Trig

INPUT1

Input

When this port receives a negative pulse, /OUTPUT1 are changed to the  Low/High level depending on the setup.

I/O2

OUTPUT1

Output

Changes to the logic level when /INPUT1 receives a negative pulse. A command can be available for altering the Low/High level logic.

Port 3

I/O1

P1

Output

Hardwired pulse train output #1 (TTL)

Trig

PULSE SYNC IN

Input

Pulse generator synchronization trigger input (TTL)

I/O2

P2

Output

Hardwired pulse train output #2 (TTL)

Port 4

I/O1

P3

Output

Hardwired pulse train output #3 (TTL)

Trig

N/A

N/A

At default, no signal is assigned to Trig on Port 4

I/O2

P4

Output

Hardwired pulse train output #4 (TTL)

Modification of Pin Assignments

The user can modify the pin assignments of digital I/O port except for the three signals; READY_FOR_TRIGGER, EXTERNAL_TRIGGER and INDEX which are assigned on the PORT1. If you have two port system, it is necessary to modify this file in order to use the signals of P1 to P4 and PULSE SYNC IN.

Save the definition file according to the following examples.  The VNA firmware first initializes the pin assignments to the default condition defined above then read the user defined file.

File name and location to save

C:\\Users\Public\Public Documents\Network Analyzer\m9485a_digitalio.csv

File format

<port number>, <signal for I/O1>, <signal for Trig>, <signal for I/O2>

 

Parameter

Value

<port number>

2 – maximum port number in the 1st chassis

<signal for I/O1>

SWEEP_END, OUTPUT1, P1, P2, P3 or P4

<signal for Trig>

INPUT1 or PULSE_SYNC_IN

<signal for I/O2>

SWEEP_END, OUTPUT1, P1, P2, P3 or P4

INPUT1 and OUTPUT1 must be assigned to the same port number

If the same signal is assigned to some of the different I/O ports, the lower port is selected. And if the same signal is assigned to the both of the I/O1 and I/O2 on the same port, the I/O1 is selected.

Example 1

2 ports system with P1,  PULSE SYNC IN, P2

(SWEEP_END, INPUT1, OUTPUT1, P3 and P4 are not used)

 

PORT1

PORT2

I/O 1

READY FOR TRIGGER

P1

Trig

EXTERNAL TRIGGER

PULSE SYNC IN

I/O 2

INDEX

P2

File format example

2, P1,PULSE_SYNC_IN,P2

Example 2

2 ports system with SWEEP_END,  PULSE SYNC IN, P1

( INPUT1, OUTPUT1, P2 to P4 are not used)

 

PORT1

PORT2

I/O 1

READY FOR TRIGGER

SWEEP_END

Trig

EXTERNAL TRIGGER

PULSE SYNC IN

I/O 2

INDEX

P1

File format example

2, SWEEP_END,PULSE_SYNC_IN,P1

Example 3

4 ports system, signal locations are assigned differently from default as shown below.

 

PORT1

PORT2

PORT3

PORT4

I/O 1

READY FOR TRIGGER

SWEEP_END

OUTPUT1

P4

Trig

EXTERNAL TRIGGER

N/A

INPUT1

PULSE SYNC IN

I/O 2

INDEX

P1

P2

P3

File format example

2, SWEEP_END,,P1

3, OUTPUT1,INPUT1,P2

4, P4,PULSE SYNC IN,P3

Restriction of the usage of M9377A I/O2

In case of the multi-chassis configuration and M9377A is used as the 1st port receiver, the I/O2 pin must be used as Sync pin to synchronize over the chassis. Then the INDEX signal cannot be output from the I/O2 of PORT1. In this special case the INDEX signal is output from the I/O1 pin of the 1st port receiver in the 2nd chassis.

Restriction of the P1 to P4 and PULSE SYNC IN

In case of the multi-chassis configuration, the P1 to P4 can be assigned to the receivers installed in the 1st chassis. The PULSE SYNC IN can be assigned to the receivers installed in the slots which belong to the same trigger bus segment of the 1st port receiver. In standard configuration, both receiver should be in slots No. 7 to 12 for M9018A. Refer to M9018A users guide for the trigger bus segment.   

 

Pin Descriptions

Input1

When this Input line receives a Low pulse from the material handler, data is latched on the OUTPUT1 lines.

The Input Line activity can be read:

SCPI

  

CONTrol:HANDler:INPut?

  

 

Output1

The current state of these latched TTL outputs may be set High or Low (Default setting) using the (non-user) OUTPUT commands.

The next state (following a negative edge on the INPUT1 line) may be pre-loaded to High or Low (Default setting) using the user commands.

For example, on the next negative pulse on the INPUT1 line, you want the OUTPUT1 line to go from 0 to 1.  To do this:

CONT:HAND:OUTP1:DATA 0  'Force the OUTPUT1 line to 0
CONT:HAND:OUTP1:USER 1  'Set the OUTPUT1:USER buffer to 1, indicating the next state

 

SCPI

  

Write User Data

CONT:HAND:OUTP1:USER

  

Read last value written

CONT:HAND:OUTP1:USER

  

Write non-user data

CONT:HAND:OUTP1:DATA

  

Read last value written

CONT:HAND:OUTP1:DATA

  

 

External Trigger

When trigger source is set to external, this Input line accepts a trigger signal from the material handler. This usually means that a part is in place and ready to be tested.

 

 

Sweep End

This output line indicates the status of the VNA sweep. The sweep includes sweeping the source and taking data.

  • Low (falling edge) indicates that the specified sweep event has finished. This does NOT indicate that all calculations have finished.

  • High indicates that the specified sweep event is active.

Set Sweep Event Mode:

  • Sweep: indicates that a single source sweep has finished. (Default setting)

  • Channel: indicates that a single channel has finished.

  • Global: indicates that all enabled channels have finished.

SCPI

  

CONTrol:HANDler:SWEepend

  

Timing Diagrams

 

Description

Minimum

Typical

T1

Pulse width of  /EXTERNAL TRIGGER

0.1 µs

 

T2

Pulse width of /SWEEP END

 

10 µs

 

 

 

Description

Minimum

Typical

T1

Pulse width of  /INPUT1

0.1 µs

 

T2

Response time of /OUTPUT1

 

0.1 µs

 

 

Last modified:

 

18-May-2016

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