IEEE-488 Option -05
Introduction
7
7-3
7-1. Introduction
The IEEE-488 Interface turns the Data Acquisition Unit 2620A into a fully
programmable instrument for use with the IEEE Standard 488.1 (1987) interface bus
(IEEE-488 bus). With the IEEE-488 Interface, the instrument can become part of an
automated instrumentation system.
The IEEE-488 Interface cannot be used with the Hydra Data Logger (2625A).
7-2. Theory of Operation
7-3.
Functional Block Description
The IEEE-488 Assembly (A5) requires power supply voltages, address, data and control
signals from the instrument Main Assembly (A1) to operate. The A5 assembly
implements the circuitry necessary to satisfy the IEEE-488.1 standard for programmable
instrumentation.
7-4. IEEE-488 PCA Detailed Circuit Description (2620A Only)
The IEEE-488 PCA comprises the following functional blocks: the Main PCA
Connector, the IEEE-488 Controller, and the IEEE-488 Transceivers and Connector.
These three blocks are described in the following paragraphs. Refer to Section 8 for a
schematic diagram of the IEEE-488 PCA.
Pin numbering for the IEEE Controller (A5U1) differs somewhat on early production
units. All A5U1 pin references in this section relate to newer production units.
Differences for early production units can be identified by referencing the manufacturer’s
number on the A5U1 chip with the information provided in Table 7-1.
Table 7-1. A5U1 Pin Differences
WD9914 (Early Production A5U1)
TMS9914A (Newer Production A5U1)
REFERENCE
NAME
NAME
REFERENCE
A5U1-1
A5U1-2
A5U1-3
A5U1-4
A5U1-5
A5U1-6
A5U1-17
A5U1-19
A5U1-20
A5U1-21
A5U1-22
A5U1-23
A5U1-24
A5U1-25
A5U1-26
A5U1-27
A5U1-28
ACCRQ*
ACCGR*
CE*
WE*
DBIN
(nc)
(nc)
D1
D0
CLK
RESET*
VSS
TE
REN
IFC
NDAC
NRFD
(nc)
ACCRQ*
ACCGR*
CD*
WE*
DBIN
D1
D0
CLK
RESET*
VSS
TE
REM
IFC
NDAC
NRFD
(nc)
A5U1-1
A5U1-2
A5U1-3
A5U1-4
A5U1-5
A5U1-6
A5U1-17
A5U1-19
A5U1-20
A5U1-21
A5U1-22
A5U1-23
A5U1-24
A5U1-25
A5U1-26
A5U1-27
A5U1-28
Summary of Contents for 2620A
Page 4: ......
Page 18: ...HYDRA Service Manual 1 2...
Page 48: ...HYDRA Service Manual 1 32...
Page 140: ...HYDRA Service Manual 3 16...
Page 234: ...HYDRA Service Manual 5A 34...
Page 236: ...HYDRA Service Manual 6 2...
Page 254: ...HYDRA Service Manual 6 20 2620A 1601 s63f eps Figure 6 3 2620A 2625A A1 Main PCA...
Page 258: ...HYDRA Service Manual 6 24 2635A 1601 s64f eps Figure 6 4 2635A A1 Main PCA...
Page 260: ...HYDRA Service Manual 6 26 2620A 4002 CKT 1 CKT 2 s65f eps Figure 6 5 A2 Display PCA...
Page 272: ...HYDRA Service Manual 6 38...
Page 274: ...HYDRA Service Manual 7 2...
Page 282: ...HYDRA Service Manual 7 10...
Page 284: ...HYDRA Service Manual 8 2...
Page 285: ...Schematic Diagrams 8 8 3 Figure 8 1 A1 Main PCA 2620A 2625A 2620A 1601 s88f eps...
Page 288: ...Schematic Diagrams 8 8 6 Figure 8 1 A1 Main PCA 2620A 2625A cont 2620A 1001 3 of 4 s73f eps...
Page 292: ...Schematic Diagrams 8 8 10 2635A 1001 2 of 5 Figure 8 2 A1 Main PCA 2635A cont s76f eps...
Page 293: ...Schematic Diagrams 8 8 11 2635A 1001 3 of 5 Figure 8 2 A1 Main PCA 2635A cont s77f eps...
Page 296: ...Schematic Diagrams 8 8 14 2620A 4002 CKT 1 CKT 2 Figure 8 3 A2 Display PCA s90f eps...
Page 300: ...Schematic Diagrams 8 8 18 2620A 1003 2 of 3 Figure 8 4 A3 A D Converter PCA cont s82c eps...
Page 301: ...Schematic Diagrams 8 8 19 2620A 1003 3 of 3 Figure 8 4 A3 A D Converter PCA cont s83c eps...
Page 302: ...Schematic Diagrams 8 8 20 2620A 1604 Figure 8 5 A4 Analog Input PCA s92f eps...
Page 304: ...Schematic Diagrams 8 8 22 2620A 1605 Figure 8 6 A5 IEEE 488 Interface PCA 2620A Only s93f eps...
Page 306: ...Schematic Diagrams 8 8 24 2625A 1606 Figure 8 7 A6 Memory PCA 2625A s94f eps...
Page 310: ...Schematic Diagrams 8 8 28...
