Siemens SIMATIC TIWAY 1 - Manual (Page 30)

OPERATION AND APPLICATION
UNILINK HOST ADAPTER 2–20
USER MANUAL
2.7 THE HIU AS A SECONDARY
The HIU function appears as a special secondary device to the NM function. In
addition to queuing network requests for the NM function to process, the HIU
function will respond to TIWAY I Primitives 02 — Machine Status, 03 —
Machine Type/Configuration, and 04 — Primitive Format Configuration. The
TIWAY I Systems Manual provides more details on the format and use of
Primitives.
2.7.1 Primitive 02 Response
The Primitive 02 response will be returned as follows (spaces were added for
clarity).
LLLL 02 HH DD EE FF
Where LLLL is the Primitive length,
HH will be 00 indicating that it is operational and
performing instruction execution,
DD will be 01 indicating that the Auxiliary Power Source
Status is not available,
EE will be 00 indicating that the NIM is operational,
FF will be 00 and has no meaning for an HIU.