2 ieee488 port – INFICON IC/5 Thin Film Deposition Controller User Manual
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IC/5 Operating Manual
7.5.2 IEEE488 Port
An IEEE488 circuit card may be purchased and installed into the IC/5,
IPN 760-142-G1. The instrument appears on the IEEE488 bus as a device. A
unique device address must be assigned. Refer to
Communication Parameters, on page 7-2
. A standard IEEE488 24-pin connector
is provided on the circuit card.
The instrument makes use of the IEEE488 status byte.
Whenever there is message available (MAV) in the instrument, bit-4 of the status
byte will be set. By enabling the automatic serial polling and checking the status
byte, very reliable data transfer between the instrument and the host computer can
be achieved. The timeouts for the device and the host should be set sufficiently
long (at least 0.5 s).
Additionally, service requests are supported. A service request is a request by the
instrument to transmit information to the host. The instrument does this by
triggering the RQS bit of the status byte. A host-initiated serial poll then identifies
the requesting device by the presence of a 1 in the RQS (2
6
) bit of the status byte.
The following conditions of the instrument can be detected by examining the low 4
bits of the status byte in combination with the bit-4.
Table 7-3 Instrument Conditions
bit position:
7
6
5
4
3
2
1
0
MAV/Data ready:
-
-
-
1
-
-
-
-
Final thickness:
-
1
-
1
0
0
0
1
Stop:
-
1
-
1
0
0
1
0
End layer:
-
1
-
1
0
0
1
1
Power up:
-
1
-
1
0
1
0
0
End Process:
-
1
-
1
0
1
0
1