GE GFK-1004B Manuel D’Utilisation

4-22

TCP/IP Ethernet Communications User’s Manual – January 1996

GFK-1004B

Retrieve Detailed Channel Status (2002)

The Retrieve Detailed Channel Status command requests that the current Detailed
Channel Status words be returned for a channel. The Detailed Channel Status words
contain an active/inactive channel indicator and the last channel error codes seen (see
Section 4 for more details). These two words of detailed status supplement the
information available in the COMMREQ Status word and the Channel Status bits. The
command has no effect on the value of the Channel Status bits.

Be aware that the Detailed Channel Status words are updated every time the status of
the channel changes. If, for example, the channel is operating with a fast repetition
period, the status words may change faster than the ladder executes the COMMREQ to
retrieve them. Therefore, some status values will be missed from the ladder’s point of
view.

Example Command Block

Retrieve detailed channel status for channel 5. Store the Detailed Channel Status words
to Registers 100-101. Return the COMMREQ Status word to %R10.

ÁÁÁÁÁ

ÁÁÁÁÁÁ

Dec (Hex)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

ÁÁÁÁÁ

Word 1

ÁÁÁÁÁÁ

00004 (0004)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Length of Channel Command Data Block (4 words)

ÁÁÁÁÁ

Word 2

ÁÁÁÁÁÁ

00000 (0000)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Always 0 (no-wait mode request)

ÁÁÁÁÁ

Word 3

ÁÁÁÁÁÁ

00008 (0008)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Memory Type of CRS word (%R)

ÁÁÁÁÁ

Word 4

ÁÁÁÁÁÁ

00009 (0009)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

CRS word address minus 1 (%R10)*

ÁÁÁÁÁ

Word 5

ÁÁÁÁÁÁ

00000 (0000)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Reserved

ÁÁÁÁÁ

Word 6

ÁÁÁÁÁÁ

00000 (0000)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Reserved

ÁÁÁÁÁ

Word 7

ÁÁÁÁÁÁ

02002 (07d2)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Retrieve Detailed Channel Status Command number

ÁÁÁÁÁ

Word 8

ÁÁÁÁÁÁ

00005 (0005)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Channel number 5

ÁÁÁÁÁ

Word 9

ÁÁÁÁÁÁ

00008 (0008)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Local PLC - memory type to store Detailed Chan. Stat. (%R)

ÁÁÁÁÁ

Word 10

ÁÁÁÁÁÁ

00100 (0064)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Local PLC - starting address (%R100)

ÁÁÁÁÁ

ÁÁÁÁÁÁ

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

* Word 4 (CRS word address) is the only zero-based address in the Command Block.

Only this address requires subtracting 1 from the intended address.

(Word 7) Channel Command Number:

The command parameter in Word 7 requests that

Detailed Channel Status words be returned. If the command is processed successfully,
the Detailed Channel Status words will be written to the location specified in Words 9
and 10. Then the CRS word will indicate successful completion of the command. If the
specified channel is not currently in use, the latest status will be returned.

(Word 8) Channel Number:

The channel number in Word 8 specifies the channel whose

status is to be read. This value must be a channel number in the range of 1 to 16 decimal.

(Word 9) Local PLC - Memory Type:

Words 9 and 10 specify the starting point in the

client CPU memory where the Detailed Channel Status words are to be written. The
length of the transfer is implied and is equal to 2 words. Section 4 describes the format
of the DCS words. Word 9 specifies the memory type (See Table 4-2).

The term local PLC is
used here to identify the
client PLC

-the PLC

that initiates the
communications
request.