Are there any standards on where in display Crew awareness system messages needs to be shown and how many messages at a time needs to be displayed. I checked SAE ARP4102-7 but I didn't find any guidance.
Yes, certainly there are standards for crew awareness messages. The number of messages displayed is normally limited by screen space allotted, which is may vary from around 5 to 15 messages and when there is a 'spillover' the messages continue on the next page. The pages are selectable via a simple cancel/recall push button and may also automatically change as corrective actions are taken by the crew or the cause/fault ceases for whatever reason. There is Colour Coding, eg red for Warnings and amber for Cautions. Green and white are also typically used for normal but temporarily used systems eg 'Anti-Ice' or Passenger signs.
All the above describe some of the features of modern crew alerting systems, for details refer to the following document:
(You might find it useful to go to Appendix 5 (Definitions), right at the end of this Advisory Circular, before reading the main body of the document. Appendix 5 makes mention using diagrams as to where in the pilots field vision the visual alert should ideally be.)
The above linked AC shows us acceptable means of complying with FAA Rule which is - 14 CFR Part 25.1322 reproduced below.
§ 25.1322 Flightcrew alerting. (a) Flightcrew alerts must:
(1) Provide the flightcrew with the information needed to:
(i) Identify non-normal operation or airplane system conditions, and
(ii) Determine the appropriate actions, if any.
(2) Be readily and easily detectable and intelligible by the flightcrew under all foreseeable operating conditions, including conditions where multiple alerts are provided.
(3) Be removed when the alerting condition no longer exists.
(b) Alerts must conform to the following prioritization hierarchy based on the urgency of flightcrew awareness and response.
(1) Warning: For conditions that require immediate flightcrew awareness and immediate flightcrew response.
(2) Caution: For conditions that require immediate flightcrew awareness and subsequent flightcrew response.
(3) Advisory: For conditions that require flightcrew awareness and may require subsequent flightcrew response.
(c) Warning and caution alerts must:
(1) Be prioritized within each category, when necessary.
(2) Provide timely attention-getting cues through at least two different senses by a combination of aural, visual, or tactile indications.
(3) Permit each occurrence of the attention-getting cues required by paragraph (c)(2) of this section to be acknowledged and suppressed, unless they are required to be continuous.
(d) The alert function must be designed to minimize the effects of false and nuisance alerts. In particular, it must be designed to:
(1) Prevent the presentation of an alert that is inappropriate or unnecessary.
(2) Provide a means to suppress an attention-getting component of an alert caused by a failure of the alerting function that interferes with the flightcrew's ability to safely operate the airplane. This means must not be readily available to the flightcrew so that it could be operated inadvertently or by habitual reflexive action. When an alert is suppressed, there must be a clear and unmistakable annunciation to the flightcrew that the alert has been suppressed.
(e) Visual alert indications must:
(1) Conform to the following color convention:
(i) Red for warning alert indications.
(ii) Amber or yellow for caution alert indications.
(iii) Any color except red or green for advisory alert indications.
(2) Use visual coding techniques, together with other alerting function elements on the flight deck, to distinguish between warning, caution, and advisory alert indications, if they are presented on monochromatic displays that are not capable of conforming to the color convention in paragraph (e)(1) of this section.
(f) Use of the colors red, amber, and yellow on the flight deck for functions other than flightcrew alerting must be limited and must not adversely affect flightcrew alerting.