Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Turbo PMAC General Purpose I/O Use
201
The analog-to-digital converters on Turbo PMAC require +5V and -12V supplies. These supplies are not
isolated from digital +5V circuitry on PMAC. If the Turbo PMAC2 is plugged into the bus (ISA, PCI, or
VME), these supplies are taken from the bus power supply. In a standalone application, these supplies
must be brought in on terminal block TB1.
isolated from digital +5V circuitry on PMAC. If the Turbo PMAC2 is plugged into the bus (ISA, PCI, or
VME), these supplies are taken from the bus power supply. In a standalone application, these supplies
must be brought in on terminal block TB1.
The -12V and matching +12V supply voltages are available on the J1 connector to supply the analog
circuitry providing the signals. The +12V supply is not used by Turbo PMAC; it is merely passed
through to the J1 connector for convenience. If use of this supply is desired, it must come either from the
bus supply through Turbo PMAC’s bus connector, or from TB1.
circuitry providing the signals. The +12V supply is not used by Turbo PMAC; it is merely passed
through to the J1 connector for convenience. If use of this supply is desired, it must come either from the
bus supply through Turbo PMAC’s bus connector, or from TB1.
Multiplexing Principle
Only one pair of analog-to-digital converter registers is available to the Turbo PMAC processor at any
given time. The data appears to the processor at address Y:$078800 on a Turbo PMAC2; it appears at
Y:$078808 on a Turbo PMAC PCI. The data from the selected analog input 0 to 7 (ANAI00-ANAI07)
appears in the low 12 bits; the data from the selected analog input 8 to 15 (ANAI08-ANAI15) appears in
the high 12 bits. This data is present only if Option 12A has been ordered.
given time. The data appears to the processor at address Y:$078800 on a Turbo PMAC2; it appears at
Y:$078808 on a Turbo PMAC PCI. The data from the selected analog input 0 to 7 (ANAI00-ANAI07)
appears in the low 12 bits; the data from the selected analog input 8 to 15 (ANAI08-ANAI15) appears in
the high 12 bits. This data is present only if Option 12A has been ordered.
The input is selected and the conversion is started by writing to this same word address Y:$078800. A
value of 0 to 7 written into the low 12 bits selects the analog input channel of that number (ANAI00-
ANAI07) to be converted in unipolar mode (0V to +5V). A value of 0 to 7 written into the high 12 bits
selects the analog input channel numbered 8 greater (ANAI08-ANAI15) in unipolar mode. If the value
written into either the low 12 bits or the high 12 bits is 8 higher (8 to 15), the same input channel is
selected, but the conversion is in bipolar mode (-2.5V to +2.5V).
value of 0 to 7 written into the low 12 bits selects the analog input channel of that number (ANAI00-
ANAI07) to be converted in unipolar mode (0V to +5V). A value of 0 to 7 written into the high 12 bits
selects the analog input channel numbered 8 greater (ANAI08-ANAI15) in unipolar mode. If the value
written into either the low 12 bits or the high 12 bits is 8 higher (8 to 15), the same input channel is
selected, but the conversion is in bipolar mode (-2.5V to +2.5V).
De-multiplexing I-Variables
Turbo PMAC I-variables I5060 – I5096 permit the automatic de-multiplexing of these multiplexed A/D
converters (and of multiplexed A/D converters on external Acc-36 and Acc-59 boards as well).
converters (and of multiplexed A/D converters on external Acc-36 and Acc-59 boards as well).
I5060 controls the number of A/D converter pairs accessed in the de-multiplexing ring, up to 16 pairs.
Variables starting at I5061, and possibly up to I5076, specify the Turbo PMAC address of each ADC pair
to be read. The addresses of all eight pairs on the JANA port are located at $078800.
Variables starting at I5061, and possibly up to I5076, specify the Turbo PMAC address of each ADC pair
to be read. The addresses of all eight pairs on the JANA port are located at $078800.
Variables starting at I5081, and possibly up to I5096, specify which pair of ADCs at the address specified
by the I-variable numbered 20 lower is read (e.g. I5081 for I5061), and how it is to be converted. I5081 –
I5096 are 24-bit values, represented by 6 hexadecimal digits. Legitimate values are of the format
$00m00n, where m and n can take any hex value from 0 through F.
by the I-variable numbered 20 lower is read (e.g. I5081 for I5061), and how it is to be converted. I5081 –
I5096 are 24-bit values, represented by 6 hexadecimal digits. Legitimate values are of the format
$00m00n, where m and n can take any hex value from 0 through F.
For the on-board Option 12 and 12A ADCs on a Turbo PMAC2, the m value determines which of the
inputs ANAI08 to ANAI15 that come with Option 12A is to be read, and how it is to be converted,
according to the following formulas:
inputs ANAI08 to ANAI15 that come with Option 12A is to be read, and how it is to be converted,
according to the following formulas:
•
8
#
ANAI
m
−
=
; 0 to +5V unipolar input
•
#
ANAI
m
=
; -2.5V to +2.5V bipolar input
For the on-board Option 12 and 12A ADCs on a Turbo PMAC2, the n value determines which of the
inputs ANAI00 to ANAI07 that come with Option 12A is to be read, and how it is to be converted,
according to the following formulas:
inputs ANAI00 to ANAI07 that come with Option 12A is to be read, and how it is to be converted,
according to the following formulas:
•
#
ANAI
n
=
; 0V to +5V unipolar input
•
8
#
ANAI
n
+
=
; -2.5V to +2.5V bipolar input
The results of this A/D de-multiplexing are placed in registers at addresses Y:$003400 to Y:$00341F,
using bits 12 to 23 of these registers. The value of the A/D converter found in the low 12 bits of the
source register is placed in the register with the even-numbered address; the value of the A/D converter
found in the high 12 bits of the source register is placed in the register with the odd-numbered address.
Refer to the Turbo PMAC memory map or I5061 – I5076 description for details. Suggested M-variables
for the result registers are M5061 – M5076.
using bits 12 to 23 of these registers. The value of the A/D converter found in the low 12 bits of the
source register is placed in the register with the even-numbered address; the value of the A/D converter
found in the high 12 bits of the source register is placed in the register with the odd-numbered address.
Refer to the Turbo PMAC memory map or I5061 – I5076 description for details. Suggested M-variables
for the result registers are M5061 – M5076.