User manual
58
© 2008, Elektro-Automatik GmbH & Co. KG
EN
About the interface cards
Service Request (SRQ) generation
The GPIB controller automatically handles the actions that
are triggered by the bit rsv in the status register STB.
After generating a service request and subsequent query
with *STB? from the host, the register is cleared.
The scheme is illustrated in the diagramm below.
A SRQ is generated as soon as the bit rsv in the Status Byte
register (STB) is set and the corresponding bits for events
that can cause a SRQ are activated in the Service Request
Enable Register (SRE).
Which events can cause a service request is selected with
the Service Request Enable Register by the command *SRE
<CHAR>.
The status register STB consists of these bits:
Bit 0: Not used
Bit 1: Not used
Bit 2: err, Error queue full; this queue is cleared by reading
it and the bit is also reset. The list can hold up to 4
of the last errors
Bit 3:
ques, Questionable status register is active (on or
more events have occured)
Bit 4: Not used
Bit 5: esr, the standard Event Status Register (ESR), mas-
ked by the Event Status Enable Register (ESE), is
signalising that one or more events have occured
Bit 6: rsv, always active
Bit 7: oper, signalises, that one or more events have
occured and are stored in the Operation Status
Register
The event bits of the various registers report to the STB, if
events have occured that are enabled to be reported, by the
corresponding bits in the enable registers (*ESE, *SRE resp.
STAT:QUES:ENAB, STAT:OPER:ENAB).
The input bits of the registers are assigned as shown in the
diagram. Red means, these signals are only available at PSI
9000 device, blue they are only available at EL3000/9000
devices.
OPC = OPeration Complete bit
EXE= EXecution Error
QYE= QuerY Error
CME= CoMmand Error
DDE= Device Depend Error
Reduce Power
Questionable Status
QUES
CV
CC
CR
LOCAL
Fct. running
EXTERNAL
Input / Output on
err
oper
U = User defined
Event
OR
Operation Status
OPER
ques
data
data
data
data
OUTPUT Buffer
mav
Service
Request
Enable
SRE
STATUS
STB
0 0
0 0
1 1
1 1
0 0
1 1
1
1 1
0
1
7
6
5
4
3
2
OR
mss
rsv
Service Request
Generation
Condition
z
0
0
z
z
z
0
z
0
1
7
6
5
4
3
2
Standard Event Status
Register
ESE ESR
Power on
OPC
EXE
CME
DDE
OR
esr
CP
Output Enable
Error
Error
0
Error Queue
<>0
Function mode
REMOTE
Fct. at start
Fct. stepping
z = State of the indicated information
D = Set after power On
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0/z
0/z
0/z
0/z
0/z
0/z
0/z
0
z
z
z
0
0/z
0
0
0
1
7
6
5
4
3
2
8
9
10
11
12
13
14
0
0
0
0
0
0
0
0
0
0
0
0
0/1
0
0
0/1
0/1
0/1
0/1
0/1
0/1
0/1
0
1
1
1
0
0/1
0
0
0/D
0/D
0/D
0/D
0/D
0/D
0/D
0
D
D
D
0
0/U
0
0
Enable
Condition
Positive transition
Negative transition
Event
OR
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
z
z
z
z
z
z
z
z
0
0
0
z
z
0
0
0
1
7
6
5
4
3
2
8
9
10
11
12
13
14
0
0
0
0
1
0
0
0
0
0
0
1
0/1
0
0
1
1
1
1
0/1
0/1
0/1
0/1
0
0
0
1
0/1
0
0
D
D
D
D
0/U
0/U
0/U
0/U
0
0
0
D
0/U
0
0
Enable
Condition
Positive transition
Negative transition
Enable
1
0
0
1
1
1
0
1
Event
0
0
0
0
0
0
0
0
MODE_A
MODE_B
MODE_AB
MODE_BAT
MODE_CR1
MODE_CR2
MODE_CV
Legend:
CC/CV/CP/CR = currently active regulation mode
Reduce Power = power derating active
Fct. at start/running/stepping = function manager status
Input / Output on = Input resp. output of the device is on
Output enable = auto-on for the output is activated
MODE_A/B/AB/BAT = actual operation mode, chosen by the rotary switch
MODE_CR1/CR2 = currently selected resistance range (CR1 is the smaller one)
LOCAL = device is in local mode, remote control is not allowed
REMOTE = device is remotely controlled by a digital interface card
EXTERNAL = device is controlled by the analogue interface card resp. the
built-in analog interface
Function mode = function manager active