User`s manual

Software Manual • EKF Intelligent I/O Controller Family On CompactPCI
- 80 -
EKF Elektronik GmbH * Philipp-Reis-Str. 4 * D-59065 HAMM (Germany)
Tel. [phone] * Fax. [phone] * E-Mail [e-mail] * Internet http://www.ekf.de
Set Amount Needed For Read: CMDIMR_READ_NEED
Description:
This command is used to set the amount of data the host needs for a
read. The port is specified by the port identifier. As soon as the
requested number of bytes are available in the read buffer, the controller
sends a message to the host.
Command Code:
9.
Command Data:
Number of bytes needed for the read.
Parameters:
None.
Data:
None.
Command Word:
0x0Y09 AAAA
Flags Port ID Command Command Data
E
R
R
R
P
L
C
P
L
U
F
ID
3
ID
2
ID
1
ID
0
C
7
C
6
C
5
C
4
C
3
C
2
C
1
C
0
D
15
D
14
D
13
D
12
D
11
D
10
D
09
D
08
D
07
D
06
D
05
D
04
D
03
D
02
D
01
D0
0
0000YYYY00001001AAAAAAAAAAAAAAAA
31 28 27 24 23 16 15 8 7 0
Reply:
Flags Port ID Command Command Data
E
R
R
R
P
L
C
P
L
U
F
ID
3
ID
2
ID
1
ID
0
C
7
C
6
C
5
C
4
C
3
C
2
C
1
C
0
D
15
D
14
D
13
D
12
D
11
D
10
D
09
D
08
D
07
D
06
D
05
D
04
D
03
D
02
D
01
D0
0
X1X0YYYY00001001AAAAAAAAAAAAAAAA
31 28 27 24 23 16 15 8 7 0
The controller returns with the RPL flag set. If there is already enough
data in the read buffer, the CPL flag is set also. Otherwise a separate
complete message is sent as soon as the requested amount of data
was received by the port. The contents of bits 15:00 in the reply word is
unchanged.
On error the RPL, CPL and ERR flags are set and an error code is
passed in bits 15:00 of the reply word.