tnt 5002 interface

[theotigan]

Jp1 is connected to GND...

i have make the test and iblines give me

EOI  ATN  SRQ  REN  IFC  NRFD  NDAC  DAC

 0        0       1        1       0        0           0          0

Thanks

[Collin M]

Can you tell me what J7 is connected to? Is this connector populated on your board? What is the function?

To clarify your last experiment, the TNT5002 is powered off and you connect it with a GPIB cable to the PCI-GPIB. Then you do an iblines on the PCI-GPIB and see SRQ is a '1'. Then you remove the GPIB cable, do another iblines and SRQ is a '0'. Can you verify that?

[theotigan]

This is my code Cant' you Check it??

void init_Gpib()
{

        // Debut

 WriteGpib(SfrRst,CMDR);        // Reset the Turbo 4882 on the TNT SftRst=0x22 

 WriteGpib(0x80,SPMR);          // Place the TnT in Turbo+7210 Mode  
 WriteGpib(0x80,AUXMR);
 WriteGpib(0x99,SPMR);
 WriteGpib(0x99,AUXMR);     

 //WriteGpib(E_ONEC,HSSEL);       // Configure the TNT for One Chip Mode
 WriteGpib(RstChip, AUXMR);     // Assert the local pon message
 WriteGpib(0x00, KEYREG);

                                // Set the Gpib Address
 WriteGpib(0x31, ADMR);

 WriteGpib(0x07, ADR0);
 WriteGpib(0xE0, ADR1);

                                         // init serial poll

 WriteGpib(0x00, SPMR);

                                           // interupt enable

WriteGpib(IE_ADSC, MR2);

 WriteGpib(E_DGB|E_DGA, HIER);  // Select the deglitching circuit for the TNT 4882 (Handshake param..) Minimun time that dav must remain continuely asserted to be detected by the aceptor maschine
 WriteGpib(HLDI, AUXMR);        // Prevent for data reception   //HLDI
 WriteGpib(PON, AUXMR);         // Clear the Local pon message  //pon  

// To receive Data from the RS232  an control it .......      

while(1)
        {

             RSendChar(LF);             //  Receive Data  über Rs232
             RSendChar(ReadGpib(ADR0));
             RSendChar(LF);

             RSendChar(LF);             //  Receive Data    über Rs232
             RSendChar(ReadGpib(ISR2));
             RSendChar(LF);

             RSendChar(LF);             //  Receive Data    über Rs232
             RSendChar(ReadGpib(BSR));
             RSendChar(LF);

        }

}

[Collin M]

I don't think the problem is with your code. Can you look at the questions in my previous post?

We need to figure out how SRQ is being asserted when the TNT5002 is powered off.

[theotigan]

J7 is no connect , is it an alternative ieee connector  to J6..   whe use  j6 or j7

Yes i have verified  and it is true.....

tnt power of and cable connected to pci Gpib -> SRQ = 1

tnt power of and cable  no connected to pci Gpib -> SRQ = 0

[Collin M]

Ok, this is an important failure and I think we should focus on it first.

The SRQ signal is an output of the TNT5002 and an input to the PCI-GPIB in this case. The SRQ signal is active low, meaning the PCI-GPIB will detect it being asserted when it is at a low voltage, less than about 0.8V.

All GPIB devices have built-in pullups inside the transceivers. These pullups pull up the signal to about 3.3V.

If you disconnect the GPIB cable and measure the SRQ signal at the PCI-GPIB you will measure about 3.3V. If you do an iblines you will see that SRQ is '0'.

When you connect the cable but do not apply power to the TNT5002 and do an iblines you see SRQ is '1'. That means the voltage on the SRQ signal is close to ground. Somewhere on the TNT5002 board there is a low impedance path (short circuit) from SRQ to ground. From our earlier testing it seems that other GPIB signals may also have this same problem.

Connecting an unpowered TNT5002 should not change the state of any GPIB signals. Also, powering on a TNT5002 and holding it in reset should not change the state of any GPIB signals.

You should determine the cause of this short circuit prior to troubleshooting anything else. Have you closely examined the soldering on the TNT5002 and GPIB connector? Can you check the resistance of SRQ to Ground by measuring SRQ directly at the TNT5002?

[theotigan]

I whill make the test and aply later

Thanks Mr Collin

[theotigan]

 Mr Collin

 I have measure the resistor between the SRQ and GND I got a infinite value

I do the same whit the other lines(ATN,EOI,IFC,NFRD,NDAC,DAV) whit the same result,  I thing none is short circuit, i have done all the measure by power off.

I alwas make this tst

I writw 0xFF to BCR Write(0xFF, BCR), I measure the voltage at the control lines pin and do a iblines at host

and I have doese result

BCR=0xFF

EOI= 0.3v, ATN=3,3v, SRQ=0.3v, REN=3.3v, IFC=3.3v NRFD=0.3v, NDAC=0.3v and

DAV= 0.3v

and iblines

EOI  ATN  SRQ  REN  IFC  NRFD  NDAC  DAV

 0        0       1        1      0     1         1         0

it look like BCR don't workt corectly?

[Collin M]

You must clear pon in order to turn the GPIB transceivers on and actually drive the signals out of the TNT5002. If you don't clear pon the TNT5002 will never drive any GPIB signal. Writing to the BCR will only change the state of a GPIB signal externally when pon is clear.

Also, the TNT5002 is not capable of driving IFC, REN, and ATN as only controllers can drive these signals.

[theotigan]

I have more information about the J7 (shematic), he is a alternative connector and he is connected to the tnt5002, also we have two connector (parallel), and we use only one....