HOST PROCESSOR RULES

Hos~ Processor Rule 1 (refer to 3.5.1):

Upon sending a text message to a station, the host processor must poll to verify proper receipt of the text. Tt)₁is poll must occur before any other text is sent to that poll group.

If the UTS 30 does not respond with an acknowledgment verifying proper receipt of the text, the host processor must resend the text message.

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Host Processor Rule 2 (refer to 3.5.1):

The host processor must send a poll with acknowledgment to a station that has sent an acknowledgeable response before the host processor can send a text message to that station.

Host Processor Rule 3 (refer to 3.6.1):

When using general polls, the host processor must expect an acknowledgment (or busy) from one station to be included with a response from another station in the poll group. The multiplexer function allows an acknowledgment to be passed from one station to another station that has a traffic response pending.

UP-9799 Rev. 1

SPERRY UTS 30 SINGLE STATION System Reference

Host Processor Rule 4 (refer to 3.6.1):

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When using general polls, the host processor must expect successive traffic responses from stations within a poll group. However, UTS 30 rule 3 still applies. The multiplexer function allows a station with a message pending to send its response to any poll whose address it recognizes.

Host Processor Rule 5 (refer to 3.6.1):

The host processor can send text to any station in the poll group that is not owed an acknowledgment, provided the last response from the poll group was not one of the following:

• OLE 1 only (SOH RID SID DID OLE 1 ETX BCC)

• OLE ? only (SOH RID SID DID OLE ? ETX BCC)'

• OLE 1 plus text available (SOH RID SID DID OLE 1 OLE 0 ETX BCC)

• OLE ? plus text available (SOH RID SID DID OLE ? OLE 0 ETX BCC) Host Processor Rule 6 (refer to 3.6.1 ):

When the host processor owes an acknowledgment to a station in a poll group, the host processor may send a specific poll to the poll group only if the specific poll is addressed to the station that is owed the acknowledgment.

Host Processor Rule 7 (refer to 3.6.1):

The host processor must not allow a given poll group to owe more than one acknowledgment to the host processor at any time.

Host Processor Rule 8 (refer to 3. 7 .1):

The host processor must treat any error in a received message as a no-response condition and must repeat the poll that preceded the no-response condition. However, any acknowledgment included with the original poll must be eliminated and a general DID must be used when the poll is repeated. If the no-response condition results from a retransmission request (OLE NAK), the host processor must repeat the poll that created the reply-request response.

Host Processor Rule 9 (refer to 3.7.1 ):

The host processor response to a reply request (OLE ENO) from a station must be a retransmission request (OLE NAK) if the last message correctly received from the station sending the reply request did not contain text data. The retransmission request has the same specific RID and specific SID address as that contained in the reply request. The retransmission request must contain a general DID.

Host Processor Rule 10 (refer to 3.7.1 ):

The host processor response to a reply request (OLE ENO) from a station must be a poll-with-acknowledgment message if the last message correctly received from the station

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System Reference UP-9799 Rev. 1

Host Processor Rule 11 (refer to 3.7.1):

The host processor response to a reply request (OLE ENO) from a station must be a retransmission request (OLE NAK) if the station sending the reply request is other than one to which an acknowledgment has just been sent.

Host Processor Rule 12 (refer to 3.7.1 ):

If the response from a retransmission request is identical to the UTS 30 response sent just previous to the reply request and is from the same station, then the response to the retransmission request can be ignored except for sending the acknowledgment that the station expects. However, the same UTS 30 response is to be ignored only once.

Host Processor Rule 13 (refer to 3.8.4):

If a no-response condition exists on a selection poll, then host processor rule 6 (which requires sending of a specific poll) must be followed. If the response to this specific poll is a reply request, then a retransmission request must be sent. If the response is no traffic, the selection poll must be resent.

Host Processor Rule 14 (refer to 3.8.4):

A selection poll can contain an acknowledgment only if the selection is being performed on the station that is owed the acknowledgment.

Host Processor Rule 15 (refer to 3.8.4):

The host processor must maintain peripheral-operation timers at the station level or at the UTS 30 to provide an indication of excessive wait time or of a sustained busy condition.

These timers must take into consideration the amount of time a station is on the PAO prior to performance of the operation (the wait time) and the amount of time required to actually perform the operation. Wait time depends on the number of host-processor and operator-initiated operations already in the PAO and the type of operations being performed.

The station-level timer should be initiated for:

• A delayed status response to a selection poll

• A OLE 1 plus delayed status response to the poll following a TEXT/SD message

• A OLE 1 plus message-queued response to the poll following a TEXT/SD/Pl message

• A OLE ? response to the poll following a TEXT/Pl or TEXT/SD/Pl message

When general polls are being used, the station-level peripheral timeouts can be used as a timing mechanism for periodically sending specific polls to determine when the peripheral operation is actually in progress (refer to UTS 30 rule 11 ).

The station-level timer should be terminated upon notification of a peripheral completion (the THRU response if the first response was OLE ·? or OLE 1 plus message queued, or the peripheral device status if the first response was delayed status).

UP-9799 Rev. 1

SPERRY UTS 30 SINGLE STATION System Reference