MULTI-LEAVING line protocol necessary for their devices to function as
remote stations. This programming support is provided by a remote
ter.inal processor (RTP) program generated according to HASP workstaticn
protocol and tailored to the system's hardware configuration. Certain
programmable remote stations like the System/3 can only be programmed to
function as remote terminals. Others, like the System/360 and System/370, can function either as reaote terminals or as host batch
systems using Rses as a remote job entry workstation= Both of these
types of remote stations are managed by the spool MULTI-LEAVING (SML) line driver of RSCS. Bonprogrammable remote stations are I/O configurations that cannot be
programmed, but are hard-wired to provide the line protocol necessary
for them to function as remote stations. They can receive, read, print,
punch, and send files. An examFle of a nonprogrammable remote staticn
is a 2780 Data Tratismission Terminal. Nonprogrammable remote staticns
are managed by the NPT (Nonprogrammable Terminal) RSCS line driver.
The tYFes of devices supported for all types of remote stations,
programmable and nonprogrammable, are listed in the VM/370 §y!de. Network Control: RSCS and VM/370 Commands Both RSCS and VM/370 commands are used to control RSCS. The RSCS commands are used to control the RSCS network; VM/370 CP and ClS commands are used by virtual machine users who use the RSCS network. RSCS COMMANDS To manipulate file being transmitted across the network and to
communicate with the various network users, the Rses control program provides a command language. Figure 2 is a list of RSCS commands and
the functions they perform. You can find detailed descriptions of these
commands in the pUblication §EQoling RSCS Introduction 3-5

The operator may enter RSCS commands descrited in Figure 2 at the RSCS virtual machine console. A subset of the co •• and language .ay te entered by operators of remote stations.
command
Name Function BACKSPAC Restarts or repositions in a backward direction the file
currently being transmitted.
CHANGE Alters one or more attributes of a file owned by RSCS. CMD Controls certain functions performed by a remote system, or controls the logging of I/O activity on a specified
link.
DEFINE Temporarily adds a new link definition to the RSCS link
table or temporarily redefines an existing link.
DELETE Temporarily deletes a link definition from the RSCS link
table. DISCONN Places RSCS in disconnect mode and optionally directs
output to another virtual machine.
DRAIN Deactivates an active communication link. FLUSH Discontinues processing the current file on the specified
link.
FREE Resumes transmission on a communication link previously
in HOLD status. FWDSPACE Repositions the file currently being transmitted in a
forward direction. HOLD Suspends file transmission on an active link without
deactivating the line. MSG Sends a message to a local or remote station. ORDER Reorders files enqueued on a specific link. PURGE Removes all or specified files from a link. QUERY Requests system information for a link, a file, or for
the system in general. START Activates a specified communication link.
TRACE Monitors line activity on a specified link.
Figure 2. RSCS Commands and Functions VM/370 CP AND CMS COMMANDS FOR RSCS The VM/370 CP TAG and SPOOL commands specify a device to he spooled and
to associate a destination location identifier (locid) with that device. SPOOL directs the file to the RSCS virtual machine. The CP CLCSE 3-6 IBM VM/370: System Logic and Problem Determination--Volume 3