External timer reference (ETR) record

An ETR provides signals that can be used to synchronize all time-of-day (TOD) clocks in an installation. Each ETR provides a number of ports that can be connected to the central processing complexes (CPC). The on-time event (OTE) signal checks that the synchronization is correct. An ETR record is recorded on the logrec data set when an ETR-related event is processed. ETR is the MVS™ generic name for the IBM® Sysplex Timer (9037).

Table 1. Format of the ETR record
Offset		Size (bytes) alignment (bits)	Field name	Description
Dec	Hex	Size (bytes) alignment (bits)	Field name	Description
0	(0)	1	A1KEY1	Class/Source:
		1010 0011		External Timer Reference Record; type = X'A1'.
1	(1)	1	A1KEY2	System/Release level:
		100. ....		OS/VS2.
		...x xxxx		Release level 0-1F.
2	(2)	1	A1SMS	Record-independent switches:
		1... ...		More records follow.
		0... ....		Last record.
		.1.. ....		Time-of-day (TOD) clock instruction issued.
		..1. ....		Record truncated.
		...1 ....		Record created by MVS/SP Version 2, 3, or 4.
		.... 1...		TIME macro issued.
		.... .xxx		Reserved.
3	(3)	3		Record-dependent switches:
		Byte 0	A1SW1	Reserved.
		Byte 1	A1SW2	Reserved.
		Byte 2	A1SW3	Reserved.
6	(6)	1	A1RCDCT	Record count:
		xxxx ....		Record sequence number.
		.... xxxx		Total number of physical records in this logical record.
7	(7)	1		Reserved.
8	(8)	4	A1DT	System date of incident.
12	(C)	4	A1TIME	System time of incident.
16	(10)	1	A1VER	Machine version code.
17	(11)	3	A1SER	Central processor serial number.
20	(14)	2	A1MOD	Central processor machine model number.
22	(16)	2	A1CEL	Reserved.
				END OF STANDARD HEADER
		Word 1		The ETR-attachment-status word
24	(18)	bits 0-15	ETRCTLRG	The current values in the ETR-attachment control register.
		Byte 0
		1... ....	CREO	Port 0 selection control.
		.1.. ....	CRE1	Port 1 selection control.
		..xx ....		Reserved.
		.... 1...	CRETR	ETR installed.
		.... .xx.		Reserved.
		.... ...1	CRAPC	Alternate port control.
		Byte 1
25	(19)	1... ....	CRP0M	Port availability change mask for port 0.
		.1.. ....	CRP1M	Port availability change mask for port 1.
		..xx x...		Reserved.
		.... .1..	CREAM	ETR alert interrupt mask.
		.... ..1.	CRESM	ETR synchronization check interrupt mask.
		.... ...1	CRSLM	Switch to local interrupt mask.
		Byte 2
26	(1A)	1... ....	CSYN	When 1, indicates that the configuration is currently in local stepping mode; otherwise, the configuration is in the ETR-stepping mode.
		.xxx ....		Reserved.
		.... 1...	CCSID	The CPC side ID of the side whose ports are currently supplying ETR signals used by the configuration.
		.... .x..		Reserved.
		.... ..1.	CCSPN	When bit 16 is 0, the port number of the stepping port; otherwise, unpredictable.
		.... ...1	CCDPN	When bit 16 is 0, the port number of the data port; otherwise, unpredictable.
		Byte 3
27	(1B)	xxxx ....	CPS0	The current port 0 state.
		.... xxxx	CPS1	The current port 1 state.
		Word 2		The ETR-data status word
28	(1C)	Bytes 0-1		Zeros.
		Byte 2
30	(1E)	xxxx ....		Reserved.
		.... 1...	OCSID	The ID of the CPC side with the active ETR port at the most recent ETR OTE.
		.... .xx.		Reserved.
		.... ...1	OCPN	The port number of the data port at the most recent ETR-data OTE.
		Byte 3
31	(1F)	1... ....	VWORD4	When 1, word 4 of the ETR attachment information is valid.
		.1.. ....	VWORD5	When 1, word 5 of the ETR attachment information is valid.
		..1. ....	VWORD6	When 1, word 6 of the ETR attachment information is valid.
		...1 ....	VWORD7	When 1, word 7 of the ETR attachment information is valid.
		.... xxxx		Reserved.
		Words 3 and 4		The TOD-clock value at last OTE.
		Word 5		The ETR-data word 1
		Byte 0
40	(28)	bits 0-7		The ETR-alert field.
		1... ....	UNTN	The untuned bit. Indicates the tuning status of the link connected to the CPC port by which the ETR data in bytes 16-31 of the ETR-attachment information block was received. When 0, all link segments in the path from the ETR to the CPC are tuned or ETR does not provide the link-tuning function. When 1, the ETR provides the link-tuning function but one or more link segments in the path are not yet tuned.
		.x.. ....		Reserved.
		..1. ....	SRV	The service request bit. When this bit changes values a value change in the reason code field occurs.
		...x xxx.		Reserved.
		.... ...1	TADJ	When this bit changes value, a time adjustment has occurred. The contents of either the biased-local-time-offset or the biased-UTC-offset field are also changed.
		Byte 1
41	(29)	xxx. ....		Reserved.
		...1 1111	SCID	The ETR-network ID. Identifies the time source for all CPCs directly connected to the ETR.
		Byte 2
42	(2A)	xxx. ....		Reserved.
		...1 1111	ID	The ETR ID of the ETR to which the CPC port that received the ETR data in bytes 16-31 of the ETR-attachment information block is connected.
		Byte 3
43	(2B)	xxx. ....		Reserved.
		...1 1111	PN	The port number of the ETR (output) port to which the CPC port that received the ETR data in bytes 16-31 of the ETR-attachment information block is immediately connected.
		Word 5		The ETR-data word 2
44	(2C)	bits 0-31	TIMEH	High order word of ETR time at last OTE.
		Word 6		The ETR-data word 3
		Byte 0
48	(30)	xxxx xxxx	RCODE	Reason code. Specifies the probable area of errors or contains information about exception conditions.
		Byte 1
49	(31)	xxx. ....		Reserved.
		...1 ....	CHAR	When 1, indicates that the ETR is coupled; otherwise, the ETR is not coupled.
		.... xxxx	BLTO	A type code that specifies the type of the master ETR.
		Byte 2
50	(32)	xxxx xxxx	BUO	The local-time-offset value, biased by . . .
		Byte 3
51	(33)	xxxx xxxx		The accumulated number of leap seconds biased by excess-128 notation.
		Word 7		The ETR-Data Word 4
		Byte 0
52	(34)	bits 0-6	EM	The sign and the magnitude of the error between the ETR time and an external time standard at the time of the last capture.
		x... ....		The error sign. When 0, the error is positive; that is, the ETR time is ahead of the absolute time. When 1, the error is negative.
		.xxx xxx.		Reserved.
		.... ...x xxxx ....	BUC	The biased-UT1 correction value.
		.... .... .... xxxx	DC	The drift code specifying the maximum long term drift rate of the ETR.
		Bytes 2 and 3
54	(36)	2	TALC	The ETR time at the last time the master ETR correctly received the signal from an external time standard.
56	(38)	Words 8-11		Reserved.
72	(48)	Word 12		Information for the Alternate Port
		Byte 0
		bits 0-7		Reserved.
		Byte 1 <
73	(49)	xxx. ....		Reserved.
		...1 1111	SCID	The ETR-network ID. Identifies the time source for all CPCs directly connected to the ETR.
		Byte 2
74	(50)	xxx. ....		Reserved.
		...1 1111	ID	The ETR ID of the ETR to which the alternate CPC port is connected.
		Byte 3
75	(51)	xxx. ....		Reserved.
		...1 1111	PN	The port number of the ETR (output) port to which the alternate CPC port is immediately connected.
76	(52)	84 bytes		Reserved.
		96 bytes		Character data containing the text of a message issued to the console or to the system log (SYSLOG).